A Squeak VM in Javascript
JavaScript Smalltalk HTML CSS Makefile Python
Latest commit 1076d2c Nov 17, 2016 @jsparkes jsparkes committed with Fix accidental use of strlen.

README.md

SqueakJS: A Squeak VM for the Web

Build Status

SqueakJS is an HTML5 runtime engine for Squeak Smalltalk written in pure JavaScript by Bert Freudenberg.

The interpreter core is in "vm.js" and plugins are in the "plugins" directory. The Just-in-Time compiler is optional ("jit.js") and can be easily replaced with your own. There are two user interfaces: the regular HTML interface lets you use SqueakJS on your own web page. Just include "squeak.js". The other interface provides a visual debugger implemented also in JavaScript using Lively. This does not use "squeak.js" but reimplements the UI in Lively Morphic.

For discussions, please use the vm-dev mailing list. Also, please visit the project home page!

Running it

Simplest

  • Run a minimal image. This is the simple demo included in this repo.
  • Or run Etoys. Everything except the image and template files is in this repo.
  • Or similarly, Scratch, also in here.
  • Go to the SqueakJS debugger page with the Lively interface.

Run your own Squeak image

  • Drag an image from your local files into the launcher.
  • You can also drag files into the Lively Debugger page.
  • ... and all the other demo pages (see above) accept dropped images, too.

Which Browser

All modern browsers should work (Chrome, Safari, IE, FireFox), though Chrome performs best currently. Safari on iPad works somewhat. YMMV. Fixes to improve browser compatibility are highly welcome!

Installing locally

Without Lively (simpler)

  • download and unpack the ZIP archive (or clone the github repo)
  • serve the SqueakJS directory using a local web server.

    TIP: If you have python try out something like

    python -m SimpleHTTPServer 9090
    
  • in your web browser, open the SqueakJS/demo/simple.html file

Now Squeak should be running. The reason for having to run from a web server is because the image is loaded with an XMLHttpRequest which does not work with a file URL. Alternatively, you could just open SqueakJS/run/index.html and drop in a local image.

In Lively (nicer for debugging)

  • install Lively
  • inside the Lively directory, make a "users/bert" folder and put the SqueakJS directory there
  • open the blank.html page using your web browser
  • get a Squeak morph from the PartsBin
  • save the world under a different name

How to modify it

In Lively

  • if you installed with Lively, use that to change the code
  • all changes take effect immediately

Without Lively

  • use any text editor
  • you have to reload the page for your changes to take effect

How to share your changes

  • easiest for me is if you create a pull request
  • otherwise, send me patches

Contributions are very welcome!

Things to work on

SqueakJS is intended to run any Squeak image. It can already load anything from the original 1996 Squeak release to the latest 2016 release. But various pieces (primitives in various plugins) are still missing, in particular media support (MIDI, 3D graphics). Also, it would be nice to make it work on as many browsers as possible, especially on mobile touch devices.

As for optimizing I think the way to go is an optimizing JIT compiler. The current JIT is very simple and does not optimize at all. Since we can't access or manipulate the JavaScript stack, we might want that compiler to inline as much as possible, but keep the call sequence flat so we can return to the browser at any time. Even better (but potentially more complicated) is actually using the JavaScript stack, just like Eliot's Stack VM uses the C stack. To make BitBlt fast, we could probably use WebGL.

To make SqueakJS useful beyond running existing Squeak images, we should use the JavaScript bridge to write a native HTML UI which would certainly be much faster than BitBlt.

Better Networking would be interesting, too. The SocketPlugin currently only allows HTTP requests. How about implementing it more generally via WebSockets? Parallelize the VM with WebWorkers?

There's a gazillion exciting things to do :)

-- Bert Freudenberg

Changelog

2016-11-08: 0.9.5 more fixes
2016-10-20: 0.9.4 fixes
2016-09-08: 0.9.3 add partial GC (5x faster become / allInstances)
2016-08-25: 0.9.2 add keyboard on iOS
2016-08-03: 0.9.1 fixes
2016-07-29: 0.9 Spur support, stdout, SpeechPlugin, zipped images
2016-06-28: 0.8.3 add SocketPlugin for http/https connections
2016-04-07: 0.8.2 better touch handling, debugging, CORS, lint
2016-01-08: 0.8.1 windows keyboard fixes, 'new' operator fixed
2015-11-24: 0.8 minor fixes
2015-08-13: 0.7.9 make work on iOS again
2015-07-18: 0.7.8 fix keyboard
2015-06-09: 0.7.7 fix thisContext
2015-04-27: 0.7.6 revert JIT, minor fixes
2015-04-14: 0.7.5 JIT optimizations by HPI students (reverted in 0.7.6)
2015-02-18: 0.7.4 make pre-release image work
2015-01-30: 0.7.3 JSBridge: fix closure callbacks
2015-01-25: 0.7.2 JSBridge: add asJSObject
2014-12-22: 0.7.1 cursor shapes
2014-12-04: 0.7 support finalization of weak references
2014-11-28: 0.6.8 JSBridge with callbacks
2014-11-20: 0.6.7 implement JavaScriptPlugin
2014-11-18: 0.6.6 implement DropPlugin
2014-11-14: 0.6.5 add generated Balloon2D plugin
2014-11-06: 0.6.4 add generic run page
2014-10-28: 0.6.3 pass options via URL
2014-10-27: add JPEG plugin 
2014-10-25: add template files
2014-10-23: 0.6.2 fixes 
2014-10-21: 0.6.1 add image segment loading 
2014-10-18: 0.6 move squeak.js out of lib dir
2014-10-13: 0.5.9 microphone support
2014-10-09: 0.5.8 fixes
2014-10-07: 0.5.7 even more plugins generated
2014-10-07: 0.5.6 add quitSqueak and onQuit
2014-10-07: 0.5.5 generated ScratchPlugin
2014-10-06: 0.5.4 replace BitBltPlugin by generated
2014-10-06: 0.5.3 SoundGenerationPlugin, Matrix2x3Plugin, FloatArrayPlugin
2014-10-05: ZipPlugin
2014-10-04: MiscPrimitivePlugin
2014-10-03: VMMakerJS generates LargeIntegersPlugin
2014-09-30: 0.5.2 more JIT
2014-09-28: 0.5.1 JIT fixes
2014-09-26: 0.5 add JIT compiler
2014-09-22: v8 optimizations
2014-09-20: 0.4.6 sound output support
2014-09-13: 0.4.5 clipboartd fixes
2014-09-12: 0.4.4 cut/copy/paste in stand-alone
2014-09-09: 0.4.3 some scratch prims
2014-09-09: 0.4.2 idle fixes
2014-09-05: 0.4.1 scratch fixes
2014-09-04: 0.4.0 runs scratch
2014-08-31: switch old/new primitives
2014-08-27: event-based input
2014-08-21: exception handling
2014-07-25: 0.3.3 fullscreen support
2014-07-18: 0.3.2 benchmarking (timfel)
2014-07-18: 0.3.1 deferred display
2014-07-16: 0.3.0 closure support
2014-07-14: 0.2.3 IE optimization (timfel)
2014-07-11: 0.2.2 drag-n-drop
2014-07-07: 0.2.1 fixes for IE11 (timfel)
2014-07-04: 0.2 runs Etoys
2014-06-27: Balloon2D (krono)
2014-06-03: stand-alone version
2014-05-29: 0.1 added version number
2014-05-27: WarpBlt
2014-05-07: image saving
2014-04-23: file support
2013-12-14: colored bitblt
2013-12-03: first pixels on screen
2013-11-29: GC
2013-11-22: runs 43 byte codes and 8 sends successfully
2013-11-07: initial commit