InfoQ Homepage News Microsoft Releases JavaScript Compatibility Study for IE, Firefox, Opera, and Safari

Microsoft Releases JavaScript Compatibility Study for IE, Firefox, Opera, and Safari

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Historically JavaScript compatibility has been a major problem for web developers. Variations between the official spec, the de-facto standard, and the various implementations have kept many a developer up all night. The end result is that many web pages don't work equally well, or at all, across browsers.

Microsoft's JScript team, keenly aware that they are part of the problem, write:

The point is that JavaScript developers shouldn’t have to detect and workaround such issues. JavaScript should work the same across all implementations. We believe this is the first step in making JavaScript better.

To make it possible to achieve such implementation conformance, the first step is knowing where the divergences are. We in the JScript team are looking into where various browser based implementations diverge, where our engine is incorrect in its interpretation of the specification, what if any de facto compatibility conventions have been reached, and the value of codifying such conventions into the standard. We’ve published the first draft of JScript Deviations from ES3 as a starting point.

The document's title, "JScript Deviations from ES3", is a bit of a misnomer. This document covers not only IE, but also the JavaScript implementations found in Firefox, Opera, and Safari. This is an in-depth study of the spec with a point by point comparison between what is suppose to happen and what actually does, for all four browsers.

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Community comments

  • This is the most beautiful ugly document I've ever seen.

    by John DeHope,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    What an ugly document. I don't think they used word 2007 to write this. Where the pretty new fonts? Where's Consolas? I was hoping to never have to see Courier New ever again. And no syntax highlighting?

    Kvetching aside, seeing a document like this come from MS is a dream come true. Now they can continue this excellent trend by... releasing fixes for all of these problems in SP3 for XP and SP1 for Vista!

  • Kudos to Microsoft

    by Rob Hasselbaum,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    Kudos for Microsoft for taking a cooperative attitude here. Even better if it leads to real change.

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