Published at LXer:

The Mozilla Foundation has released an early beta of the upcoming version 4 of Firefox, its flagship cross-platform browser for Windows, OS X, and Linux. HTML 5 and CSS 3, the standards that are slated to power next-generation Websites, are clearly at the forefront of Mozilla's development efforts. Firefox 4 includes extended support for many of the new features that those two technologies introduce, including the Websocket API, which enables Web-based applications to access servers using arbitrary protocols like, for example, the one used by e-mail clients. Most interestingly, Mozilla has chosen to support HTML 5 video playback by implementing Google's WebM video codec, which, like Firefox, is open-source and (at least in theory) unencumbered by patents.

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http://annevankesteren.nl/2010/12/we...-vulnerability

"Adam Barth reported on vulnerabilities with the current WebSocket protocol handshake. Reportedly you can poison the cache of transparant/intercepting proxies affecting all users of that proxy. So rather than e.g. http://www.google-analytics.com/ga.js you would get a JavaScript file from an attacker. This attack affects Flash and Java as well, but we have higher standards for browsers.

This means that until the new WebSocket protocol handshake is sorted out by the IETF it will be behind a preference in Opera. (The same is true for Firefox.)"