ECMAScript 4 Edition Progress Spreadsheet
John Resig, Mozilla's JavaScript Evangelist and creator of jQuery, has created a spreadsheet to track the progress of the various implementations of ECMAScript 4th Edition. There are about a half-dozen implementations in development, including the reference implementation that the ECMAScript working group is developing. Here's a brief description of the implementations so that you know what's what when you take a gander at the spreadsheet:
- ES4 RI: This is the ECMAScript 4th Edition reference implementation that the ES4 working group is developing. It is written in Standard ML '97, except for the library of core classes, which is written in ES4 itself.
- Tamarin: This began life as the AVM2 (ActionScript Virtual Machine 2), but morphed into Tamarin when the AVM2 was released as open source and handed over to Mozilla for hosting and coordination. Tamarin will serve as the VM for future versions of Flash Player as well as future versions of the FireFox web browser.
- Spidermonkey: This is a JavaScript engine hosted by Mozilla. It provides scripting support in many applications, some of which are Mozilla FireFox, Yahoo! Widgets, Adobe Acrobat, and Adobe Flash CS3 (allows scripting control of the Flash authoring tool with JSFL).
- Rhino: This is another Mozilla JavaScript engine, but this one is written entirely in Java and is intended for use in applications rather than in browsers.
- Futhark: This is a JavaScript engine developed by Opera Software for use in Opera's browser versions 9.5 and 10.0.
- Mbedthis: Mbedthis specializes in embedded web server solutions and is developing EJScript 3.0, which is based on ES4.
- JSCore: This is short for JavaScriptCore, which is the JavaScript engine in WebKit.
Yet another set of columns in the spreadsheet indicates the current thinking of several companies that participate in the ES4 working group. It uses color coding to indicate whether a particular feature is high or low priority for a given company. So far, Adobe, Google, Mozilla and Mbedthis have filled out these columns. Apple has indicated that they will have their column filled out by the end of the week. These columns are not binding in any way, but will be used to inform further discussions about the various proposals.
Here's the link to the ES4 progress spreadsheet again, in case you missed it at the top of the post: