diff --git a/.gitignore b/.gitignore
index bdf973f033..e965f02426 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
 /target
-wasm/target
 **/*.rs.bk
 **/*.bytecode
 __pycache__
diff --git a/.travis.yml b/.travis.yml
index 2a28c7ef57..f9ec114857 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,3 @@
-
 language: rust
 
 rust:
@@ -7,85 +6,87 @@ rust:
   - nightly
 
 script:
-    - cargo build --verbose --all
-    - cargo test --verbose --all
+  - cargo build --verbose --all
+  - cargo test --verbose --all
 
 env:
-    # This is used to only capture the regular nightly test in allow_failures
-    - REGULAR_TEST=true
+  # This is used to only capture the regular nightly test in allow_failures
+  - REGULAR_TEST=true
 
 cache: cargo
 
 matrix:
-    include:
-        # To test the snippets, we use Travis' Python environment (because
-        # installing rust ourselves is a lot easier than installing Python)
-        - language: python
-          python: 3.6
-          cache:
-              pip: true
-              # Because we're using the Python Travis environment, we can't use
-              # the built-in cargo cacher
-              directories:
-                  - /home/travis/.cargo
-                  - target
-          env:
-              - TRAVIS_RUST_VERSION=stable
-              - REGULAR_TEST=false
-          script: tests/.travis-runner.sh
-        - language: python
-          python: 3.6
-          cache:
-              pip: true
-              # Because we're using the Python Travis environment, we can't use
-              # the built-in cargo cacher
-              directories:
-                  - /home/travis/.cargo
-                  - target
-          env:
-              - TRAVIS_RUST_VERSION=beta
-              - REGULAR_TEST=false
-          script: tests/.travis-runner.sh
-        - name: rustfmt
-          language: rust
-          rust: stable
-          cache: cargo
-          before_script:
-              - rustup component add rustfmt-preview
-          script:
-              # Code references the generated python.rs, so put something in
-              # place to make `cargo fmt` happy.  (We use `echo` rather than
-              # `touch` because rustfmt complains about the empty file touch
-              # creates.)
-              - echo > parser/src/python.rs
-              - cargo fmt --all -- --check
-          env:
-              - REGULAR_TEST=false
-        - name: publish documentation
-          language: rust
-          rust: stable
-          cache: cargo
-          script: 
-              - cargo doc --no-deps --all
-          if: branch = release
-          env:
-              - REGULAR_TEST=false
-        - name: WASM online demo
-          language: rust
-          rust: nightly
-          cache: cargo
-          install:
-            - nvm install node
-            - curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh # install wasm-pack
-          script:
-              - cd wasm
-              - bash release.sh
-          if: branch = release
-          env:
-              - REGULAR_TEST=false
-    allow_failures:
-        - rust: nightly
-          env: REGULAR_TEST=true
+  include:
+    # To test the snippets, we use Travis' Python environment (because
+    # installing rust ourselves is a lot easier than installing Python)
+    - language: python
+      python: 3.6
+      cache:
+        pip: true
+        # Because we're using the Python Travis environment, we can't use
+        # the built-in cargo cacher
+        directories:
+          - /home/travis/.cargo
+          - target
+      env:
+        - TRAVIS_RUST_VERSION=stable
+        - REGULAR_TEST=false
+      script: tests/.travis-runner.sh
+    - language: python
+      python: 3.6
+      cache:
+        pip: true
+        # Because we're using the Python Travis environment, we can't use
+        # the built-in cargo cacher
+        directories:
+          - /home/travis/.cargo
+          - target
+      env:
+        - TRAVIS_RUST_VERSION=beta
+        - REGULAR_TEST=false
+      script: tests/.travis-runner.sh
+    - name: rustfmt
+      language: rust
+      rust: stable
+      cache: cargo
+      before_script:
+        - rustup component add rustfmt-preview
+      script:
+        # Code references the generated python.rs, so put something in
+        # place to make `cargo fmt` happy.  (We use `echo` rather than
+        # `touch` because rustfmt complains about the empty file touch
+        # creates.)
+        - echo > parser/src/python.rs
+        - cargo fmt --all -- --check
+      env:
+        - REGULAR_TEST=false
+    - name: publish documentation
+      language: rust
+      rust: stable
+      cache: cargo
+      script:
+        - cargo doc --no-deps --all
+      if: branch = release
+      env:
+        - REGULAR_TEST=false
+    - name: WASM online demo
+      language: rust
+      rust: nightly
+      cache: cargo
+      install:
+        - nvm install node
+        # install wasm-pack
+        - curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+      script:
+        - cd wasm/demo
+        - npm install
+        - npm run dist
+      if: branch = release
+      env:
+        - REGULAR_TEST=false
+  allow_failures:
+    - rust: nightly
+      env: REGULAR_TEST=true
 
 deploy:
   - provider: pages
@@ -93,16 +94,18 @@ deploy:
     target-branch: master
     local-dir: target/doc
     skip-cleanup: true
-    github-token: $WEBSITE_GITHUB_TOKEN  # Set in the settings page of your repository, as a secure variable
+    # Set in the settings page of your repository, as a secure variable
+    github-token: $WEBSITE_GITHUB_TOKEN
     keep-history: true
     on:
       branch: release
   - provider: pages
     repo: RustPython/demo
     target-branch: master
-    local-dir: wasm/app/dist
+    local-dir: wasm/demo/dist
     skip-cleanup: true
-    github-token: $WEBSITE_GITHUB_TOKEN  # Set in the settings page of your repository, as a secure variable
+    # Set in the settings page of your repository, as a secure variable
+    github-token: $WEBSITE_GITHUB_TOKEN
     keep-history: true
     on:
       branch: release
diff --git a/Cargo.lock b/Cargo.lock
index 80f179fc31..ddc013a582 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -136,7 +136,7 @@ name = "caseless"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-normalization 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -230,10 +230,22 @@ dependencies = [
  "atty 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "atty 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "termcolor 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "failure"
 version = "0.1.2"
@@ -286,6 +298,14 @@ dependencies = [
  "typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "heck"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-segmentation 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "humantime"
 version = "1.1.1"
@@ -307,6 +327,14 @@ name = "itoa"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "js-sys"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "wasm-bindgen 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "kernel32-sys"
 version = "0.2.2"
@@ -426,6 +454,14 @@ name = "nodrop"
 version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "nom"
+version = "4.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "num-bigint"
 version = "0.2.1"
@@ -596,19 +632,19 @@ dependencies = [
  "aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "regex"
-version = "1.0.0"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -674,7 +710,7 @@ dependencies = [
  "num-complex 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustpython_parser 0.0.1",
  "serde 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -682,6 +718,18 @@ dependencies = [
  "statrs 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rustpython_wasm"
+version = "0.1.0"
+dependencies = [
+ "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustpython_parser 0.0.1",
+ "rustpython_vm 0.1.0",
+ "wasm-bindgen 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "web-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rustyline"
 version = "2.1.0"
@@ -749,6 +797,11 @@ name = "siphasher"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "sourcefile"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "statrs"
 version = "0.10.0"
@@ -808,6 +861,16 @@ dependencies = [
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "syn"
+version = "0.15.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "synstructure"
 version = "0.9.0"
@@ -836,6 +899,14 @@ dependencies = [
  "wincolor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "termcolor"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "wincolor 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "termion"
 version = "1.5.1"
@@ -856,11 +927,10 @@ dependencies = [
 
 [[package]]
 name = "thread_local"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -921,6 +991,89 @@ name = "void"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "wasm-bindgen-macro 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-shared 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-macro-support 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-backend 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-shared 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "wasm-bindgen-webidl"
+version = "0.2.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "failure 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "heck 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-backend 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "weedle 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "web-sys"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "env_logger 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "failure 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sourcefile 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-webidl 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "weedle"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nom 4.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
@@ -945,6 +1098,14 @@ name = "winapi-i686-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
@@ -958,6 +1119,15 @@ dependencies = [
  "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "wincolor"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [metadata]
 "checksum aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d6531d44de723825aa81398a6415283229725a00fa30713812ab9323faa82fc4"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
@@ -989,6 +1159,7 @@ dependencies = [
 "checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum ena 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cabe5a5078ac8c506d3e4430763b1ba9b609b1286913e7d08e581d1c2de9b7e5"
 "checksum env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "0e6e40ebb0e66918a37b38c7acab4e10d299e0463fe2af5d29b9cc86710cfd2a"
+"checksum env_logger 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "afb070faf94c85d17d50ca44f6ad076bce18ae92f0037d350947240a36e9d42e"
 "checksum failure 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7efb22686e4a466b1ec1a15c2898f91fa9cb340452496dca654032de20ff95b9"
 "checksum failure_derive 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "946d0e98a50d9831f5d589038d2ca7f8f455b1c21028c0db0e84116a12696426"
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
@@ -996,9 +1167,11 @@ dependencies = [
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum generic-array 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef25c5683767570c2bbd7deba372926a55eaae9982d7726ee2a1050239d45b9d"
+"checksum heck 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ea04fa3ead4e05e51a7c806fc07271fdbde4e246a6c6d1efd52e72230b771b82"
 "checksum humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0484fda3e7007f2a4a0d9c3a703ca38c71c54c55602ce4660c419fd32e188c9e"
 "checksum itertools 0.7.8 (registry+https://github.com/rust-lang/crates.io-index)" = "f58856976b776fedd95533137617a02fb25719f40e7d9b01c7043cd65474f450"
 "checksum itoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "5adb58558dcd1d786b5f0bd15f3226ee23486e24b7b58304b60f64dc68e62606"
+"checksum js-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58cfec35fd4a94f3cf357d5cb7da71c71cd52720c2f2a7320090a8db5f06f655"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lalrpop 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ba451f7bd819b7afc99d4cf4bdcd5a4861e64955ba9680ac70df3a50625ad6cf"
 "checksum lalrpop-snap 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)" = "60013fd6be14317d43f47658b1440956a9ca48a9ed0257e0e0a59aac13e43a1f"
@@ -1011,6 +1184,7 @@ dependencies = [
 "checksum new_debug_unreachable 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0cdc457076c78ab54d5e0d6fa7c47981757f1e34dc39ff92787f217dede586c4"
 "checksum nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d37e713a259ff641624b6cb20e3b12b2952313ba36b6823c0f16e6cfd9e5de17"
 "checksum nodrop 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "9a2228dca57108069a5262f2ed8bd2e82496d2e074a06d1ccc7ce1687b6ae0a2"
+"checksum nom 4.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9c349f68f25f596b9f44cf0e7c69752a5c633b0550c3ff849518bfba0233774a"
 "checksum num-bigint 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "10b8423ea72ec64751198856a853e07b37087cfc9b53a87ecb19bff67b6d1320"
 "checksum num-complex 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "107b9be86cd2481930688277b675b0114578227f034674726605b8a482d8baf8"
 "checksum num-integer 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "e83d528d2677f0518c570baf2b7abdcf0cd2d248860b68507bdcb3e91d4c0cea"
@@ -1033,7 +1207,7 @@ dependencies = [
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
 "checksum redox_users 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "214a97e49be64fd2c86f568dd0cb2c757d2cc53de95b273b6ad0a1c908482f26"
 "checksum regex 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9329abc99e39129fcceabd24cf5d85b4671ef7c29c50e972bc5afe32438ec384"
-"checksum regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "75ecf88252dce580404a22444fc7d626c01815debba56a7f4f536772a5ff19d3"
+"checksum regex 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3d8c9f33201f46669484bacc312b00e7541bed6aaf296dffe2bb4e0ac6b8ce2a"
 "checksum regex-syntax 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8e931c58b93d86f080c734bfd2bce7dd0079ae2331235818133c8be7f422e20e"
 "checksum regex-syntax 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7d707a4fa2637f2dca2ef9fd02225ec7661fe01a53623c1e6515b6916511f7a7"
 "checksum regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8f1ac0f60d675cc6cf13a20ec076568254472551051ad5dd050364d70671bf6b"
@@ -1046,6 +1220,7 @@ dependencies = [
 "checksum serde_json 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)" = "44dd2cfde475037451fa99b7e5df77aa3cfd1536575fa8e7a538ab36dcde49ae"
 "checksum sha2 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9eb6be24e4c23a84d7184280d2722f7f2731fcdd4a9d886efbfe4413e4847ea0"
 "checksum siphasher 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "0df90a788073e8d0235a67e50441d47db7c8ad9debd91cbf43736a2a92d36537"
+"checksum sourcefile 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4bf77cb82ba8453b42b6ae1d692e4cdc92f9a47beaf89a847c8be83f4e328ad3"
 "checksum statrs 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "10102ac8d55e35db2b3fafc26f81ba8647da2e15879ab686a67e6d19af2685e8"
 "checksum string_cache 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "25d70109977172b127fe834e5449e5ab1740b9ba49fa18a2020f509174f25423"
 "checksum string_cache_codegen 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "35293b05cf1494e8ddd042a7df6756bf18d07f42d234f32e71dce8a7aabb0191"
@@ -1053,12 +1228,14 @@ dependencies = [
 "checksum strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d15c810519a91cf877e7e36e63fe068815c678181439f2f29e2562147c3694"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
 "checksum syn 0.14.9 (registry+https://github.com/rust-lang/crates.io-index)" = "261ae9ecaa397c42b960649561949d69311f08eeaea86a65696e6e46517cf741"
+"checksum syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)" = "9545a6a093a3f0bd59adb472700acc08cad3776f860f16a897dfce8c88721cbc"
 "checksum synstructure 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "85bb9b7550d063ea184027c9b8c20ac167cd36d3e06b3a40bceb9d746dc1a7b7"
 "checksum term 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "fa63644f74ce96fbeb9b794f66aff2a52d601cbd5e80f4b97123e3899f4570f1"
 "checksum termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "adc4587ead41bf016f11af03e55a624c06568b5a19db4e90fde573d805074f83"
+"checksum termcolor 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4096add70612622289f2fdcdbd5086dc81c1e2675e6ae58d6c4f62a16c6d7f2f"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
 "checksum textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0b59b6b4b44d867f1370ef1bd91bfb262bf07bf0ae65c202ea2fbc16153b693"
-"checksum thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279ef31c19ededf577bfd12dfae728040a21f635b06a24cd670ff510edd38963"
+"checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
 "checksum typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "612d636f949607bdf9b123b4a6f6d966dedf3ff669f7f045890d3a4a73948169"
 "checksum ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fd2be2d6639d0f8fe6cdda291ad456e23629558d466e2789d2c3e9892bda285d"
 "checksum unicode-normalization 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "6a0180bc61fc5a987082bfa111f4cc95c4caff7f9799f3e46df09163a937aa25"
@@ -1070,9 +1247,19 @@ dependencies = [
 "checksum utf8parse 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8772a4ccbb4e89959023bc5b7cb8623a795caa7092d99f3aa9501b9484d4557d"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
+"checksum wasm-bindgen 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)" = "91f95b8f30407b9ca0c2de157281d3828bbed1fc1f55bea6eb54f40c52ec75ec"
+"checksum wasm-bindgen-backend 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)" = "ab7c242ebcb45bae45340986c48d1853eb2c1c52ff551f7724951b62a2c51429"
+"checksum wasm-bindgen-macro 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)" = "6e353f83716dec9a3597b5719ef88cb6c9e461ec16528f38aa023d3224b4e569"
+"checksum wasm-bindgen-macro-support 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)" = "3cc90b65fe69c3dd5a09684517dc79f42b847baa2d479c234d125e0a629d9b0a"
+"checksum wasm-bindgen-shared 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)" = "a71a37df4f5845025f96f279d20bbe5b19cbcb77f5410a3a90c6c544d889a162"
+"checksum wasm-bindgen-webidl 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)" = "b064b8b2336b5a6bf5f31bc95fc1310842395df29877d910cb6f8f791070f319"
+"checksum web-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7d7c588c2e5a091bc4532c5a87032955f9133b644e868b54d08ead0185dcc5b9"
+"checksum weedle 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "26a4c67f132386d965390b8a734d5d10adbcd30eb5cc74bd9229af8b83f10044"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "773ef9dcc5f24b7d850d0ff101e542ff24c3b090a9768e03ff889fdef41f00fd"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+"checksum winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "afc5508759c5bf4285e61feb862b6083c8480aec864fa17a81fdec6f69b461ab"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 "checksum wincolor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "eeb06499a3a4d44302791052df005d5232b927ed1a9658146d842165c4de7767"
+"checksum wincolor 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "561ed901ae465d6185fa7864d63fbd5720d0ef718366c9a4dc83cf6170d7e9ba"
diff --git a/Cargo.toml b/Cargo.toml
index 2bd834312c..23b9e02a5a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.0.1"
 authors = ["Windel Bouwman", "Shing Lyu <shing.lyu@gmail.com>"]
 
 [workspace]
+members = [".", "vm", "wasm/lib", "parser"]
 
 [dependencies]
 log="0.4.1"
@@ -12,3 +13,6 @@ clap = "2.31.2"
 rustpython_parser = {path = "parser"}
 rustpython_vm = {path = "vm"}
 rustyline = "2.1.0"
+
+[profile.release]
+opt-level = "s"
diff --git a/README.md b/README.md
index 4776605dd2..92623e8dba 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 # RustPython
-A Python-3  (CPython >= 3.5.0) Interpreter written in Rust :snake: :scream: :metal:.
+
+A Python-3 (CPython >= 3.5.0) Interpreter written in Rust :snake: :scream: :metal:.
 
 [![Build Status](https://travis-ci.org/RustPython/RustPython.svg?branch=master)](https://travis-ci.org/RustPython/RustPython)
 [![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](https://opensource.org/licenses/MIT)
@@ -24,7 +25,6 @@ Or use the interactive shell:
     >>>>> 2+2
     4
 
-
 # Goals
 
 - Full Python-3 environment entirely in Rust (not CPython bindings)
@@ -51,13 +51,13 @@ If you wish to update the online documentation. Push directly to the `release` b
 
 - `parser/src`: python lexing, parsing and ast
 - `vm/src`: python virtual machine
-    - `builtins.rs`: Builtin functions
-    - `compile.rs`: the python compiler from ast to bytecode
-    - `obj`: python builtin types
+  - `builtins.rs`: Builtin functions
+  - `compile.rs`: the python compiler from ast to bytecode
+  - `obj`: python builtin types
 - `src`: using the other subcrates to bring rustpython to life.
 - `docs`: documentation (work in progress)
 - `py_code_object`: CPython bytecode to rustpython bytecode convertor (work in progress)
-- `wasm`: Binary crate and resources for WebAssembly build 
+- `wasm`: Binary crate and resources for WebAssembly build
 - `tests`: integration test snippets
 
 # Contributing
@@ -68,7 +68,7 @@ Most tasks are listed in the [issue tracker](https://github.com/RustPython/RustP
 Check issues labeled with `good first issue` if you wish to start coding.
 
 Another approach is to checkout the sourcecode: builtin functions and object methods are often the simplest
-and easiest way to contribute. 
+and easiest way to contribute.
 
 You can also simply run
 `cargo run tests/snippets/whats_left_to_implement.py` to assist in finding any
@@ -135,44 +135,51 @@ cd emsdk-portable/
 
 ## Build
 
-Move into the `wasm` directory. This contains a custom library crate optimized for wasm build of RustPython.   
+Move into the `wasm` directory. This directory contains a library crate for interop
+with python to rust to js and back in `wasm/lib`, the demo website found at
+https://rustpython.github.io/demo in `wasm/demo`, and an example of how to use
+the crate as a library in one's own JS app in `wasm/example`.
 
-```bash
+```sh
 cd wasm
 ```
 
-For testing on a development server, you can run the `build.sh` script. For release build which generates files for deploying to a HTTP server, run `release.sh`.
+Go to the demo directory. This is the best way of seeing the changes made to either
+the library or the JS demo, as the `rustpython_wasm` module is set to the global
+JS variable `rp` on the website.
 
-If you don't want to use the above scripts, you can do it manually as follows:
-
-Run the build. This can take several minutes depending on the machine.
-
-```
-wasm-pack build
+```sh
+cd demo
 ```
 
-Upon successful build, cd in the the `/pkg` directory and run:
+Now, start the webpack development server. It'll compile the crate and then
+the demo app. This will likely take a long time, both the wasm-pack portion and
+the webpack portion (from after it says "Your crate has been correctly compiled"),
+so be patient.
 
-```
-npm link
+```sh
+npm run dev
 ```
 
-Now move back out into the `/app` directory. The files here have been adapted from [wasm-pack-template](https://github.com/rustwasm/wasm-pack-template).
+You can now open the webpage on https://localhost:8080 and Python code in either
+the text box or browser devtools with:
 
-Finally, run:
-
-```
-npm install
-npm link rustpython_wasm
+```js
+rp.pyEval(
+  `
+print(js_vars['a'] * 9)
+`,
+  {
+    vars: {
+      a: 9
+    }
+  }
+);
 ```
 
-and you will be able to run the files with:
-
-```
-node_modules/.bin/webpack-dev-server
-```
-
-Now open the webpage on https://localhost:8080, you'll be able to run Python code in the text box.
+Alternatively, you can run `npm run build` to build the app once, without watching
+for changes, or `npm run dist` to build the app in release mode, both for the
+crate and webpack.
 
 # Code style
 
@@ -195,4 +202,3 @@ These are some useful links to related projects:
 - https://github.com/ProgVal/pythonvm-rust
 - https://github.com/shinglyu/RustPython
 - https://github.com/windelbouwman/rspython
-
diff --git a/wasm/.gitignore b/wasm/.gitignore
index 882d44992f..3542b58965 100644
--- a/wasm/.gitignore
+++ b/wasm/.gitignore
@@ -1,2 +1,5 @@
 bin/
 pkg/
+dist/
+node_modules/
+
diff --git a/wasm/app/.prettierrc b/wasm/.prettierrc
similarity index 100%
rename from wasm/app/.prettierrc
rename to wasm/.prettierrc
diff --git a/wasm/app/.gitignore b/wasm/app/.gitignore
deleted file mode 100644
index 1eae0cf670..0000000000
--- a/wasm/app/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-dist/
-node_modules/
diff --git a/wasm/app/bootstrap.js b/wasm/app/bootstrap.js
deleted file mode 100644
index 61136ee9b8..0000000000
--- a/wasm/app/bootstrap.js
+++ /dev/null
@@ -1,6 +0,0 @@
-// A dependency graph that contains any wasm must all be imported
-// asynchronously. This `bootstrap.js` file does the single async import, so
-// that no one else needs to worry about it again.
-import('./index.js').catch(e =>
-  console.error('Error importing `index.js`:', e)
-);
diff --git a/wasm/app/index.html b/wasm/app/index.html
deleted file mode 100644
index f46ce1251a..0000000000
--- a/wasm/app/index.html
+++ /dev/null
@@ -1,89 +0,0 @@
-<!DOCTYPE html>
-<html>
-    <head>
-        <meta charset="utf-8" />
-        <title>RustPython Demo</title>
-        <style type="text/css" media="screen">
-            textarea {
-                font-family: monospace;
-                resize: vertical;
-            }
-
-            #code {
-                height: 35vh;
-                width: 95vw;
-            }
-
-            #console {
-                height: 35vh;
-                width: 95vw;
-            }
-
-            #run-btn {
-                width: 6em;
-                height: 2em;
-                font-size: 24px;
-            }
-
-            #error {
-                color: tomato;
-                margin-top: 10px;
-                font-family: monospace;
-            }
-        </style>
-    </head>
-    <body>
-        <h1>RustPython Demo</h1>
-        <p>
-            RustPython is a Python interpreter writter in Rust. This demo is
-            compiled from Rust to WebAssembly so it runs in the browser
-        </p>
-        <p>Please input your python code below and click <kbd>Run</kbd>:</p>
-        <p>
-            Alternatively, open up your browser's devtools and play with
-            <code>rp.eval_py('print("a")')</code>
-        </p>
-        <textarea id="code">
-n1 = 0
-n2 = 1
-count = 0
-until = 10
-
-print("These are the first " + str(until) + " number in a Fibonacci sequence:")
-
-while count < until:
-    print(n1)
-    n1, n2 = n2, n1 + n2
-    count += 1
-
-        </textarea>
-        <button id="run-btn">Run &#9655;</button>
-        <div id="error"></div>
-        <script src="./bootstrap.js"></script>
-        <h3>Standard Output</h3>
-        <textarea id="console">Loading...</textarea>
-
-        <p>Here's some info regarding the <code>rp.eval_py()</code> function</p>
-        <ul>
-            <li>
-                You can return variables from python and get them returned to
-                JS, with the only requirement being that they're serializable
-                with <code>json.dumps</code>.
-            </li>
-            <li>
-                You can pass an object as the second argument to the function,
-                and that will be available in python as the variable
-                <code>js_vars</code>. Again, only values that can be serialized
-                with <code>JSON.stringify()</code> will go through.
-            </li>
-        </ul>
-
-        <!-- "Fork me on GitHub" banner -->
-        <a href="https://github.com/RustPython/RustPython"
-            ><img
-                style="position: absolute; top: 0; right: 0; border: 0;"
-                src="https://s3.amazonaws.com/github/ribbons/forkme_right_green_007200.png"
-                alt="Fork me on GitHub"
-        /></a>
-    </body>
-</html>
diff --git a/wasm/app/index.js b/wasm/app/index.js
deleted file mode 100644
index d21ac7a045..0000000000
--- a/wasm/app/index.js
+++ /dev/null
@@ -1,27 +0,0 @@
-import * as rp from 'rustpython_wasm';
-
-// so people can play around with it
-window.rp = rp;
-
-function runCodeFromTextarea(_) {
-    const consoleElement = document.getElementById('console');
-    const errorElement = document.getElementById('error');
-
-    // Clean the console and errors
-    consoleElement.value = '';
-    errorElement.textContent = '';
-
-    const code = document.getElementById('code').value;
-    try {
-        rp.run_from_textbox(code);
-    } catch (e) {
-        errorElement.textContent = e;
-        console.error(e);
-    }
-}
-
-document
-    .getElementById('run-btn')
-    .addEventListener('click', runCodeFromTextarea);
-
-runCodeFromTextarea(); // Run once for demo
diff --git a/wasm/app/package.json b/wasm/app/package.json
deleted file mode 100644
index a1f9c41912..0000000000
--- a/wasm/app/package.json
+++ /dev/null
@@ -1,27 +0,0 @@
-{
-  "name": "app",
-  "version": "1.0.0",
-  "description": "",
-  "main": "index.js",
-  "dependencies": {
-    "hello-wasm-pack": "^0.1.0",
-    "webpack": "^4.16.3",
-    "webpack-cli": "^3.1.0",
-    "webpack-dev-server": "^3.1.5",
-    "copy-webpack-plugin": "^4.5.2"
-  },
-  "devDependencies": {},
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/RustPython/RustPython.git"
-  },
-  "author": "Ryan Liddle",
-  "license": "MIT",
-  "bugs": {
-    "url": "https://github.com/RustPython/RustPython/issues"
-  },
-  "homepage": "https://github.com/RustPython/RustPython#readme"
-}
diff --git a/wasm/app/webpack.config.js b/wasm/app/webpack.config.js
deleted file mode 100644
index 80ad8142d2..0000000000
--- a/wasm/app/webpack.config.js
+++ /dev/null
@@ -1,14 +0,0 @@
-const CopyWebpackPlugin = require("copy-webpack-plugin");
-const path = require('path');
-
-module.exports = {
-  entry: "./bootstrap.js",
-  output: {
-    path: path.resolve(__dirname, "dist"),
-    filename: "bootstrap.js",
-  },
-  mode: "development",
-  plugins: [
-    new CopyWebpackPlugin(['index.html'])
-  ],
-};
diff --git a/wasm/build.sh b/wasm/build.sh
deleted file mode 100644
index bc8dba97f1..0000000000
--- a/wasm/build.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-wasm-pack build --debug && \
-cd pkg && \
-npm link && \
-cd ../app && \
-npm install && \
-npm link rustpython_wasm && \
-node_modules/.bin/webpack-dev-server
diff --git a/wasm/demo/package.json b/wasm/demo/package.json
new file mode 100644
index 0000000000..97583dd6da
--- /dev/null
+++ b/wasm/demo/package.json
@@ -0,0 +1,34 @@
+{
+    "name": "app",
+    "version": "1.0.0",
+    "description": "Bindings to the RustPython library for WebAssembly",
+    "main": "index.js",
+    "dependencies": {
+        "codemirror": "^5.42.0"
+    },
+    "devDependencies": {
+        "@wasm-tool/wasm-pack-plugin": "0.2.0",
+        "webpack": "^4.16.3",
+        "webpack-cli": "^3.1.0",
+        "webpack-dev-server": "^3.1.5",
+        "copy-webpack-plugin": "^4.5.2",
+        "mini-css-extract-plugin": "^0.5.0",
+        "html-webpack-plugin": "^3.2.0",
+        "css-loader": "^2.0.1"
+    },
+    "scripts": {
+        "dev": "webpack-dev-server -d",
+        "build": "webpack",
+        "dist": "webpack --mode production"
+    },
+    "repository": {
+        "type": "git",
+        "url": "git+https://github.com/RustPython/RustPython.git"
+    },
+    "author": "Ryan Liddle",
+    "license": "MIT",
+    "bugs": {
+        "url": "https://github.com/RustPython/RustPython/issues"
+    },
+    "homepage": "https://github.com/RustPython/RustPython#readme"
+}
diff --git a/wasm/demo/src/index.html b/wasm/demo/src/index.html
new file mode 100644
index 0000000000..0b64564632
--- /dev/null
+++ b/wasm/demo/src/index.html
@@ -0,0 +1,75 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="utf-8" />
+        <title>RustPython Demo</title>
+    </head>
+    <body>
+        <h1>RustPython Demo</h1>
+        <p>
+            RustPython is a Python interpreter writter in Rust. This demo is
+            compiled from Rust to WebAssembly so it runs in the browser. <br />
+            Please input your python code below and click <kbd>Run</kbd>, or you
+            can open up your browser's devtools and play with
+            <code>rp.pyEval('print("a")')</code>
+        </p>
+        <textarea id="code">
+n1 = 0
+n2 = 1
+count = 0
+until = 10
+
+print("These are the first {} numbers in a Fibonacci sequence:".format(until))
+
+while count < until:
+    print(n1)
+    n1, n2 = n2, n1 + n2
+    count += 1
+</textarea
+        >
+        <button id="run-btn">Run &#9655;</button>
+        <div id="error"></div>
+        <h3>Standard Output</h3>
+        <textarea id="console" readonly>Loading...</textarea>
+
+        <p>Here's some info regarding the <code>rp.pyEval()</code> function</p>
+        <ul>
+            <li>
+                You can return variables from python and get them returned to
+                JS, with the only requirement being that they're serializable
+                with <code>json.dumps</code>.
+            </li>
+            <li>
+                You can pass an options object as the second argument to the
+                function:
+                <ul>
+                    <li>
+                        <code>stdout</code>: either a string with a css selector
+                        to a textarea element or a function that recieves a
+                        string when the <code>print</code> function is called in
+                        python. The default value is <code>console.log</code>.
+                    </li>
+                    <li>
+                        <code>vars</code>: an object that will be available in
+                        python as the variable <code>js_vars</code>. Only
+                        functions and values that can be serialized with
+                        <code>JSON.stringify()</code> will go through.
+                    </li>
+                </ul>
+            </li>
+            <li>
+                JS functions that get passed to python will recieve positional
+                args as positional args and kwargs as the
+                <code>this</code> argument
+            </li>
+        </ul>
+
+        <a href="https://github.com/RustPython/RustPython">
+            <img
+                style="position: absolute; top: 0; right: 0; border: 0;"
+                src="https://s3.amazonaws.com/github/ribbons/forkme_right_green_007200.png"
+                alt="Fork me on GitHub"
+            />
+        </a>
+    </body>
+</html>
diff --git a/wasm/demo/src/index.js b/wasm/demo/src/index.js
new file mode 100644
index 0000000000..bf5257df2a
--- /dev/null
+++ b/wasm/demo/src/index.js
@@ -0,0 +1,10 @@
+import './style.css';
+import 'codemirror/lib/codemirror.css';
+
+// A dependency graph that contains any wasm must all be imported
+// asynchronously. This `index.js` file does the single async import, so
+// that no one else needs to worry about it again.
+import('./main.js').catch(e => {
+    console.error('Error importing `main.js`:', e);
+    document.getElementById('error').textContent = e;
+});
diff --git a/wasm/demo/src/main.js b/wasm/demo/src/main.js
new file mode 100644
index 0000000000..d8934b5c10
--- /dev/null
+++ b/wasm/demo/src/main.js
@@ -0,0 +1,49 @@
+import * as rp from '../../lib/pkg';
+import CodeMirror from 'codemirror';
+import 'codemirror/mode/python/python';
+import 'codemirror/addon/comment/comment';
+
+// so people can play around with it
+window.rp = rp;
+
+const editor = CodeMirror.fromTextArea(document.getElementById('code'), {
+    extraKeys: {
+        'Ctrl-Enter': runCodeFromTextarea,
+        'Cmd-Enter': runCodeFromTextarea,
+        'Shift-Tab': 'indentLess',
+        'Ctrl-/': 'toggleComment',
+        'Cmd-/': 'toggleComment'
+    },
+    lineNumbers: true,
+    mode: 'text/x-python',
+    indentUnit: 4,
+    autofocus: true
+});
+
+function runCodeFromTextarea() {
+    const consoleElement = document.getElementById('console');
+    const errorElement = document.getElementById('error');
+
+    // Clean the console and errors
+    consoleElement.value = '';
+    errorElement.textContent = '';
+
+    const code = editor.getValue();
+    try {
+        const result = rp.pyEval(code, {
+            stdout: '#console'
+        });
+        if (result !== null) {
+            consoleElement.value += `\n${result}\n`;
+        }
+    } catch (e) {
+        errorElement.textContent = e;
+        console.error(e);
+    }
+}
+
+document
+    .getElementById('run-btn')
+    .addEventListener('click', runCodeFromTextarea);
+
+runCodeFromTextarea(); // Run once for demo
diff --git a/wasm/demo/src/style.css b/wasm/demo/src/style.css
new file mode 100644
index 0000000000..9fadc7c2db
--- /dev/null
+++ b/wasm/demo/src/style.css
@@ -0,0 +1,27 @@
+textarea {
+    font-family: monospace;
+    resize: none;
+}
+
+#code,
+#console {
+    height: 30vh;
+    width: calc(100% - 3px);
+}
+
+.CodeMirror {
+    border: 1px solid #ddd;
+    height: 30vh !important;
+}
+
+#run-btn {
+    width: 6em;
+    height: 2em;
+    font-size: 24px;
+}
+
+#error {
+    color: tomato;
+    margin-top: 10px;
+    font-family: monospace;
+}
diff --git a/wasm/demo/webpack.config.js b/wasm/demo/webpack.config.js
new file mode 100644
index 0000000000..6d114d4363
--- /dev/null
+++ b/wasm/demo/webpack.config.js
@@ -0,0 +1,30 @@
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+const WasmPackPlugin = require('@wasm-tool/wasm-pack-plugin');
+const path = require('path');
+
+module.exports = {
+    entry: './src/index.js',
+    output: {
+        path: path.join(__dirname, 'dist'),
+        filename: 'index.js'
+    },
+    mode: 'development',
+    module: {
+        rules: [
+            { test: /\.css$/, use: [MiniCssExtractPlugin.loader, 'css-loader'] }
+        ]
+    },
+    plugins: [
+        new HtmlWebpackPlugin({
+            filename: 'index.html',
+            template: 'src/index.html'
+        }),
+        new MiniCssExtractPlugin({
+            filename: 'styles.css'
+        }),
+        new WasmPackPlugin({
+            crateDirectory: path.join(__dirname, '../lib')
+        })
+    ]
+};
diff --git a/wasm/example/index.html b/wasm/example/index.html
new file mode 100644
index 0000000000..86a99c42f1
--- /dev/null
+++ b/wasm/example/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <meta http-equiv="X-UA-Compatible" content="ie=edge" />
+        <title>RustPython Basic Example</title>
+    </head>
+    <body>
+        <script src="./dist/app.js"></script>
+    </body>
+</html>
diff --git a/wasm/example/package.json b/wasm/example/package.json
new file mode 100644
index 0000000000..cee4b7702b
--- /dev/null
+++ b/wasm/example/package.json
@@ -0,0 +1,18 @@
+{
+    "name": "rustpython-wasm-example",
+    "version": "1.0.0",
+    "//1": "`dependencies.rustpython_wasm` would be the version of the npm",
+    "//2": "library in a real app",
+    "dependencies": {
+        "rustpython_wasm": "file:../lib/pkg/"
+    },
+    "devDependencies": {
+        "raw-loader": "1.0.0",
+        "webpack": "4.28.2",
+        "webpack-cli": "^3.1.2"
+    },
+    "scripts": {
+        "build": "webpack"
+    },
+    "license": "MIT"
+}
diff --git a/wasm/example/src/index.js b/wasm/example/src/index.js
new file mode 100644
index 0000000000..6480aaf3e7
--- /dev/null
+++ b/wasm/example/src/index.js
@@ -0,0 +1,6 @@
+// A dependency graph that contains any wasm must all be imported
+// asynchronously. This `index.js` file does the single async import, so
+// that no one else needs to worry about it again.
+import('./main.js').catch(e => {
+    console.error('Error importing `main.js`:', e);
+});
diff --git a/wasm/example/src/main.js b/wasm/example/src/main.js
new file mode 100644
index 0000000000..fcd32165e8
--- /dev/null
+++ b/wasm/example/src/main.js
@@ -0,0 +1,11 @@
+import * as py from 'rustpython_wasm';
+import pyCode from 'raw-loader!./main.py';
+
+fetch('https://github-trending-api.now.sh/repositories')
+    .then(r => r.json())
+    .then(repos => {
+        const result = py.pyEval(pyCode, {
+            vars: { repos }
+        });
+        alert(result);
+    });
diff --git a/wasm/example/src/main.py b/wasm/example/src/main.py
new file mode 100644
index 0000000000..e2d590a3f3
--- /dev/null
+++ b/wasm/example/src/main.py
@@ -0,0 +1,8 @@
+repos = js_vars['repos']
+
+star_sum = 0
+
+for repo in repos:
+    star_sum += repo['stars']
+
+return 'Average github trending star count: ' + str(star_sum / len(repos))
diff --git a/wasm/example/webpack.config.js b/wasm/example/webpack.config.js
new file mode 100644
index 0000000000..9a6f41e9e3
--- /dev/null
+++ b/wasm/example/webpack.config.js
@@ -0,0 +1,12 @@
+const path = require('path');
+
+module.exports = {
+    entry: './src/index.js',
+    mode: 'development',
+    output: {
+        path: path.join(__dirname, 'dist'),
+        filename: 'app.js',
+        publicPath: '/dist/'
+    },
+    devtool: 'cheap-module-eval-source-map'
+};
diff --git a/wasm/Cargo.lock b/wasm/lib/Cargo.lock
similarity index 100%
rename from wasm/Cargo.lock
rename to wasm/lib/Cargo.lock
diff --git a/wasm/Cargo.toml b/wasm/lib/Cargo.toml
similarity index 55%
rename from wasm/Cargo.toml
rename to wasm/lib/Cargo.toml
index 4be409dfc2..6c78e06405 100644
--- a/wasm/Cargo.toml
+++ b/wasm/lib/Cargo.toml
@@ -2,16 +2,16 @@
 name = "rustpython_wasm"
 version = "0.1.0"
 authors = ["Ryan Liddle <ryan@rmliddle.com>"]
+license = "MIT"
+description = "A Python-3 (CPython >= 3.5.0) Interpreter written in Rust, compiled to WASM"
+repository = "https://github.com/RustPython/RustPython/tree/master/wasm/lib"
 
 [lib]
 crate-type = ["cdylib", "rlib"]
 
-[workspace]
-members = []
-
 [dependencies]
-rustpython_parser = {path = "../parser"}
-rustpython_vm = {path = "../vm"}
+rustpython_parser = {path = "../../parser"}
+rustpython_vm = {path = "../../vm"}
 cfg-if = "0.1.2"
 wasm-bindgen = "0.2"
 js-sys = "0.3"
@@ -19,7 +19,3 @@ js-sys = "0.3"
 [dependencies.web-sys]
 version = "0.3"
 features = [ "console", "Document", "Element", "HtmlTextAreaElement", "Window" ]
-
-
-[profile.release]
-opt-level = "s"
diff --git a/wasm/lib/README.md b/wasm/lib/README.md
new file mode 100644
index 0000000000..b278e8cb94
--- /dev/null
+++ b/wasm/lib/README.md
@@ -0,0 +1,37 @@
+# RustPython
+
+A Python-3 (CPython >= 3.5.0) Interpreter written in Rust.
+
+[![Build Status](https://travis-ci.org/RustPython/RustPython.svg?branch=master)](https://travis-ci.org/RustPython/RustPython)
+[![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](https://opensource.org/licenses/MIT)
+[![Contributors](https://img.shields.io/github/contributors/RustPython/RustPython.svg)](https://github.com/RustPython/RustPython/graphs/contributors)
+[![Gitter](https://badges.gitter.im/RustPython/Lobby.svg)](https://gitter.im/rustpython/Lobby)
+
+## Usage
+
+### Check out our [online demo](https://rustpython.github.io/demo/) running on WebAssembly.
+
+## Goals
+
+-   Full Python-3 environment entirely in Rust (not CPython bindings)
+-   A clean implementation without compatibility hacks
+
+## Quick Documentation
+
+```js
+pyEval(code, options?);
+```
+
+`code`: `string`: The Python code to run
+
+`options`:
+
+-   `vars?`: `{ [key: string]: any }`: Variables passed to the VM that can be
+    accessed in Python with the variable `js_vars`. Functions do work, and
+    recieve the Python kwargs as the `this` argument.
+-   `stdout?`: `(out: string) => void`: A function to replace the native print
+    function, by default `console.log`.
+
+## License
+
+This project is licensed under the MIT license.
diff --git a/wasm/lib/src/lib.rs b/wasm/lib/src/lib.rs
new file mode 100644
index 0000000000..4bc0891b2f
--- /dev/null
+++ b/wasm/lib/src/lib.rs
@@ -0,0 +1,236 @@
+mod wasm_builtins;
+
+extern crate js_sys;
+extern crate rustpython_vm;
+extern crate wasm_bindgen;
+extern crate web_sys;
+
+use js_sys::{Array, Object, Reflect, TypeError};
+use rustpython_vm::compile;
+use rustpython_vm::pyobject::{self, PyFuncArgs, PyObjectRef, PyResult};
+use rustpython_vm::VirtualMachine;
+use wasm_bindgen::{prelude::*, JsCast};
+
+// Hack to comment out wasm-bindgen's typescript definitons
+#[wasm_bindgen(typescript_custom_section)]
+const TS_CMT_START: &'static str = "/*";
+
+fn py_str_err(vm: &mut VirtualMachine, py_err: &PyObjectRef) -> String {
+    vm.to_pystr(&py_err)
+        .unwrap_or_else(|_| "Error, and error getting error message".into())
+}
+
+fn py_to_js(vm: &mut VirtualMachine, py_obj: PyObjectRef) -> JsValue {
+    let dumps = rustpython_vm::import::import(
+        vm,
+        std::path::PathBuf::default(),
+        "json",
+        &Some("dumps".into()),
+    )
+    .expect("Couldn't get json.dumps function");
+    match vm.invoke(dumps, pyobject::PyFuncArgs::new(vec![py_obj], vec![])) {
+        Ok(value) => {
+            let json = vm.to_pystr(&value).unwrap();
+            js_sys::JSON::parse(&json).unwrap_or(JsValue::UNDEFINED)
+        }
+        Err(_) => JsValue::UNDEFINED,
+    }
+}
+
+fn js_to_py(vm: &mut VirtualMachine, js_val: JsValue) -> PyObjectRef {
+    if js_val.is_object() {
+        if Array::is_array(&js_val) {
+            let js_arr: Array = js_val.into();
+            let elems = js_arr
+                .values()
+                .into_iter()
+                .map(|val| js_to_py(vm, val.expect("Iteration over array failed")))
+                .collect();
+            vm.ctx.new_list(elems)
+        } else {
+            let dict = vm.new_dict();
+            for pair in Object::entries(&Object::from(js_val)).values() {
+                let pair = pair.expect("Iteration over object failed");
+                let key = Reflect::get(&pair, &"0".into()).unwrap();
+                let val = Reflect::get(&pair, &"1".into()).unwrap();
+                let py_val = js_to_py(vm, val);
+                vm.ctx
+                    .set_item(&dict, &String::from(js_sys::JsString::from(key)), py_val);
+            }
+            dict
+        }
+    } else if js_val.is_function() {
+        let func = js_sys::Function::from(js_val);
+        vm.ctx.new_rustfunc(
+            move |vm: &mut VirtualMachine, args: PyFuncArgs| -> PyResult {
+                let func = func.clone();
+                let this = Object::new();
+                for (k, v) in args.kwargs {
+                    Reflect::set(&this, &k.into(), &py_to_js(vm, v))
+                        .expect("Couldn't set this property");
+                }
+                let js_args = Array::new();
+                for v in args.args {
+                    js_args.push(&py_to_js(vm, v));
+                }
+                func.apply(&this, &js_args)
+                    .map(|val| js_to_py(vm, val))
+                    .map_err(|err| js_to_py(vm, err))
+            },
+        )
+    } else if let Some(err) = js_val.dyn_ref::<js_sys::Error>() {
+        let exc_type = match String::from(err.name()).as_str() {
+            "TypeError" => &vm.ctx.exceptions.type_error,
+            "ReferenceError" => &vm.ctx.exceptions.name_error,
+            "SyntaxError" => &vm.ctx.exceptions.syntax_error,
+            _ => &vm.ctx.exceptions.exception_type,
+        }
+        .clone();
+        vm.new_exception(exc_type, err.message().into())
+    } else if js_val.is_undefined() {
+        // Because `JSON.stringify(undefined)` returns undefined
+        vm.get_none()
+    } else {
+        let loads = rustpython_vm::import::import(
+            vm,
+            std::path::PathBuf::default(),
+            "json",
+            &Some("loads".into()),
+        )
+        .expect("Couldn't get json.loads function");
+
+        let json = match js_sys::JSON::stringify(&js_val) {
+            Ok(json) => String::from(json),
+            Err(_) => return vm.get_none(),
+        };
+        let py_json = vm.new_str(json);
+
+        vm.invoke(loads, pyobject::PyFuncArgs::new(vec![py_json], vec![]))
+            // can safely unwrap because we know it's valid JSON
+            .unwrap()
+    }
+}
+
+fn base_scope(vm: &mut VirtualMachine) -> PyObjectRef {
+    let builtins = vm.get_builtin_scope();
+    vm.context().new_scope(Some(builtins))
+}
+
+fn eval(vm: &mut VirtualMachine, source: &str, vars: PyObjectRef) -> PyResult {
+    // HACK: if the code doesn't end with newline it crashes.
+    let mut source = source.to_string();
+    if !source.ends_with('\n') {
+        source.push('\n');
+    }
+
+    let code_obj = compile::compile(vm, &source, compile::Mode::Exec, None)?;
+
+    vm.run_code_obj(code_obj, vars)
+}
+
+#[wasm_bindgen(js_name = pyEval)]
+/// Evaluate Python code
+///
+/// ```js
+/// pyEval(code, options?);
+/// ```
+///
+/// `code`: `string`: The Python code to run
+///
+/// `options`:
+///
+/// -   `vars?`: `{ [key: string]: any }`: Variables passed to the VM that can be
+///     accessed in Python with the variable `js_vars`. Functions do work, and
+///     recieve the Python kwargs as the `this` argument.
+/// -   `stdout?`: `(out: string) => void`: A function to replace the native print
+///     function, by default `console.log`.
+pub fn eval_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
+    let options = options.unwrap_or_else(|| Object::new());
+    let js_vars = {
+        let prop = Reflect::get(&options, &"vars".into())?;
+        if prop.is_undefined() {
+            None
+        } else if prop.is_object() {
+            Some(Object::from(prop))
+        } else {
+            return Err(TypeError::new("vars must be an object").into());
+        }
+    };
+    let stdout = {
+        let prop = Reflect::get(&options, &"stdout".into())?;
+        if prop.is_undefined() {
+            None
+        } else {
+            Some(prop)
+        }
+    };
+    let mut vm = VirtualMachine::new();
+
+    let print_fn: Box<Fn(&mut VirtualMachine, PyFuncArgs) -> PyResult> = match stdout {
+        Some(val) => {
+            if let Some(selector) = val.as_string() {
+                Box::new(
+                    move |vm: &mut VirtualMachine, args: PyFuncArgs| -> PyResult {
+                        wasm_builtins::builtin_print_html(vm, args, &selector)
+                    },
+                )
+            } else if val.is_function() {
+                let func = js_sys::Function::from(val);
+                Box::new(
+                    move |vm: &mut VirtualMachine, args: PyFuncArgs| -> PyResult {
+                        func.call1(
+                            &JsValue::UNDEFINED,
+                            &wasm_builtins::format_print_args(vm, args)?.into(),
+                        )
+                        .map_err(|err| js_to_py(vm, err))?;
+                        Ok(vm.get_none())
+                    },
+                )
+            } else {
+                return Err(TypeError::new("stdout must be a function or a css selector").into());
+            }
+        }
+        None => Box::new(wasm_builtins::builtin_print_console),
+    };
+
+    vm.ctx.set_attr(
+        &vm.builtins,
+        "print",
+        vm.ctx.new_rustfunc_from_box(print_fn),
+    );
+
+    let mut vars = base_scope(&mut vm);
+
+    let injections = vm.new_dict();
+
+    if let Some(js_vars) = js_vars.clone() {
+        for pair in Object::entries(&js_vars).values() {
+            let pair = pair?;
+            let key = Reflect::get(&pair, &"0".into()).unwrap();
+            let val = Reflect::get(&pair, &"1".into()).unwrap();
+            let py_val = js_to_py(&mut vm, val);
+            vm.ctx.set_item(
+                &injections,
+                &String::from(js_sys::JsString::from(key)),
+                py_val,
+            );
+        }
+    }
+
+    vm.ctx.set_item(&mut vars, "js_vars", injections);
+
+    eval(&mut vm, source, vars)
+        .map(|value| py_to_js(&mut vm, value))
+        .map_err(|err| py_str_err(&mut vm, &err).into())
+}
+
+#[wasm_bindgen(typescript_custom_section)]
+const TYPESCRIPT_DEFS: &'static str = r#"
+*/
+export interface PyEvalOptions {
+    stdout: (out: string) => void;
+    vars: { [key: string]: any };
+}
+
+export function pyEval(code: string, options?: PyEvalOptions): any;
+"#;
diff --git a/wasm/src/wasm_builtins.rs b/wasm/lib/src/wasm_builtins.rs
similarity index 52%
rename from wasm/src/wasm_builtins.rs
rename to wasm/lib/src/wasm_builtins.rs
index 99e59f6bee..ca3ab013aa 100644
--- a/wasm/src/wasm_builtins.rs
+++ b/wasm/lib/src/wasm_builtins.rs
@@ -8,47 +8,53 @@ extern crate js_sys;
 extern crate wasm_bindgen;
 extern crate web_sys;
 
+use crate::js_to_py;
 use js_sys::Array;
-use rustpython_vm::obj::objstr;
-use rustpython_vm::pyobject::{PyFuncArgs, PyResult};
+use rustpython_vm::pyobject::{PyFuncArgs, PyObjectRef, PyResult};
 use rustpython_vm::VirtualMachine;
-use wasm_bindgen::JsCast;
+use wasm_bindgen::{JsCast, JsValue};
 use web_sys::{console, window, HtmlTextAreaElement};
 
 // The HTML id of the textarea element that act as our STDOUT
-const CONSOLE_ELEMENT_ID: &str = "console";
 
-pub fn print_to_html(text: &str) {
+pub fn print_to_html(text: &str, selector: &str) -> Result<(), JsValue> {
     let document = window().unwrap().document().unwrap();
     let element = document
-        .get_element_by_id(CONSOLE_ELEMENT_ID)
-        .expect("Can't find the console textarea");
-    let textarea = element.dyn_ref::<HtmlTextAreaElement>().unwrap();
+        .query_selector(selector)?
+        .ok_or_else(|| js_sys::TypeError::new("Couldn't get element"))?;
+    let textarea = element
+        .dyn_ref::<HtmlTextAreaElement>()
+        .ok_or_else(|| js_sys::TypeError::new("Element must be a textarea"))?;
     let value = textarea.value();
     textarea.set_value(&format!("{}{}", value, text));
+    Ok(())
 }
 
-pub fn builtin_print_html(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+pub fn format_print_args(vm: &mut VirtualMachine, args: PyFuncArgs) -> Result<String, PyObjectRef> {
+    let mut output = String::new();
     let mut first = true;
     for a in args.args {
         if first {
             first = false;
         } else {
-            print_to_html(&" ")
+            output.push_str(" ");
         }
-        let v = vm.to_str(&a)?;
-        let s = objstr::get_value(&v);
-        print_to_html(&format!("{}\n", s))
+        output.push_str(&vm.to_pystr(&a)?);
+        output.push('\n');
     }
+    Ok(output)
+}
+
+pub fn builtin_print_html(vm: &mut VirtualMachine, args: PyFuncArgs, selector: &str) -> PyResult {
+    let output = format_print_args(vm, args)?;
+    print_to_html(&output, selector).map_err(|err| js_to_py(vm, err))?;
     Ok(vm.get_none())
 }
 
 pub fn builtin_print_console(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     let arr = Array::new();
-    for a in args.args {
-        let v = vm.to_str(&a)?;
-        let s = objstr::get_value(&v);
-        arr.push(&s.into());
+    for arg in args.args {
+        arr.push(&vm.to_pystr(&arg)?.into());
     }
     console::log(&arr);
     Ok(vm.get_none())
diff --git a/wasm/lib/target b/wasm/lib/target
new file mode 120000
index 0000000000..6bcd2fc5d2
--- /dev/null
+++ b/wasm/lib/target
@@ -0,0 +1 @@
+../../target
\ No newline at end of file
diff --git a/wasm/release.sh b/wasm/release.sh
deleted file mode 100644
index ea5b388c6f..0000000000
--- a/wasm/release.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-wasm-pack build && \
-cd pkg && \
-npm link && \
-cd ../app && \
-npm install && \
-npm link rustpython_wasm && \
-node_modules/.bin/webpack --mode production && \
-echo "Output saved to app/dist"
diff --git a/wasm/src/lib.rs b/wasm/src/lib.rs
deleted file mode 100644
index 9ac5677d79..0000000000
--- a/wasm/src/lib.rs
+++ /dev/null
@@ -1,143 +0,0 @@
-mod wasm_builtins;
-
-extern crate js_sys;
-extern crate rustpython_vm;
-extern crate wasm_bindgen;
-extern crate web_sys;
-
-use rustpython_vm::compile;
-use rustpython_vm::pyobject::{self, PyObjectRef, PyResult};
-use rustpython_vm::VirtualMachine;
-use wasm_bindgen::prelude::*;
-use web_sys::console;
-
-fn py_str_err(vm: &mut VirtualMachine, py_err: &PyObjectRef) -> String {
-    vm.to_pystr(&py_err)
-        .unwrap_or_else(|_| "Error, and error getting error message".into())
-}
-
-fn py_to_js(vm: &mut VirtualMachine, py_obj: PyObjectRef) -> JsValue {
-    let dumps = rustpython_vm::import::import(
-        vm,
-        std::path::PathBuf::default(),
-        "json",
-        &Some("dumps".into()),
-    )
-    .expect("Couldn't get json.dumps function");
-    match vm.invoke(dumps, pyobject::PyFuncArgs::new(vec![py_obj], vec![])) {
-        Ok(value) => {
-            let json = vm.to_pystr(&value).unwrap();
-            js_sys::JSON::parse(&json).unwrap_or(JsValue::UNDEFINED)
-        }
-        Err(_) => JsValue::UNDEFINED,
-    }
-}
-
-fn js_to_py(vm: &mut VirtualMachine, js_val: JsValue) -> PyObjectRef {
-    let json = match js_sys::JSON::stringify(&js_val) {
-        Ok(json) => String::from(json),
-        Err(_) => return vm.get_none(),
-    };
-
-    let loads = rustpython_vm::import::import(
-        vm,
-        std::path::PathBuf::default(),
-        "json",
-        &Some("loads".into()),
-    )
-    .expect("Couldn't get json.loads function");
-
-    let py_json = vm.new_str(json);
-
-    vm.invoke(loads, pyobject::PyFuncArgs::new(vec![py_json], vec![]))
-        // can safely unwrap because we know it's valid JSON
-        .unwrap()
-}
-
-fn eval<F>(vm: &mut VirtualMachine, source: &str, setup_scope: F) -> PyResult
-where
-    F: Fn(&mut VirtualMachine, &PyObjectRef),
-{
-    // HACK: if the code doesn't end with newline it crashes.
-    let mut source = source.to_string();
-    if !source.ends_with('\n') {
-        source.push('\n');
-    }
-
-    let code_obj = compile::compile(vm, &source, compile::Mode::Exec, None)?;
-
-    let builtins = vm.get_builtin_scope();
-    let mut vars = vm.context().new_scope(Some(builtins));
-
-    setup_scope(vm, &mut vars);
-
-    vm.run_code_obj(code_obj, vars)
-}
-
-#[wasm_bindgen]
-pub fn eval_py(source: &str, js_injections: Option<js_sys::Object>) -> Result<JsValue, JsValue> {
-    if let Some(js_injections) = js_injections.clone() {
-        if !js_injections.is_object() {
-            return Err(js_sys::TypeError::new("The second argument must be an object").into());
-        }
-    }
-
-    let mut vm = VirtualMachine::new();
-
-    vm.ctx.set_attr(
-        &vm.builtins,
-        "print",
-        vm.context()
-            .new_rustfunc(wasm_builtins::builtin_print_console),
-    );
-
-    let res = eval(&mut vm, source, |vm, vars| {
-        let injections = if let Some(js_injections) = js_injections.clone() {
-            js_to_py(vm, js_injections.into())
-        } else {
-            vm.new_dict()
-        };
-
-        vm.ctx.set_item(vars, "js_vars", injections);
-    });
-
-    res.map(|value| py_to_js(&mut vm, value))
-        .map_err(|err| py_str_err(&mut vm, &err).into())
-}
-
-#[wasm_bindgen]
-pub fn run_from_textbox(source: &str) -> Result<JsValue, JsValue> {
-    //add hash in here
-    console::log_1(&"Running RustPython".into());
-    console::log_1(&"Running code:".into());
-    console::log_1(&source.to_string().into());
-
-    let mut vm = VirtualMachine::new();
-
-    // We are monkey-patching the builtin print to use console.log
-    // TODO: monkey-patch sys.stdout instead, after print actually uses sys.stdout
-    vm.ctx.set_attr(
-        &vm.builtins,
-        "print",
-        vm.context().new_rustfunc(wasm_builtins::builtin_print_html),
-    );
-
-    match eval(&mut vm, source, |_, _| {}) {
-        Ok(value) => {
-            console::log_1(&"Execution successful".into());
-            match value.borrow().kind {
-                pyobject::PyObjectKind::None => {}
-                _ => {
-                    if let Ok(text) = vm.to_pystr(&value) {
-                        wasm_builtins::print_to_html(&text);
-                    }
-                }
-            }
-            Ok(JsValue::UNDEFINED)
-        }
-        Err(err) => {
-            console::log_1(&"Execution failed".into());
-            Err(py_str_err(&mut vm, &err).into())
-        }
-    }
-}