Aug 27, 2010 16:15 GMT  ·  By

Having released the fourth Beta development milestone of Firefox 4.0, Mozilla is currently focusing on building the Beta 5 release, while gearing up to the feature freeze stage in the browser’s evolution. Essentially, the browser vendor is getting ready to decide the feature set that will make it into the final version of Firefox 4.0.

In this regard, some features that have been proposed for the next major iteration of Mozilla’s open source browser might not actually be included into the final version of Firefox 3.6’s successor.

Mozilla certainly has a lot on its hands when it comes down to delivering Firefox 4.0. And fact is that the deadline for the official release is getting closer and closer.

Firefox 4.0 needs to be wrapped up by the end of 2010, and this means that the launch deadline is 3 – 4 months away at least. Yet, Mozilla still has to deliver Firefox 4.0 Beta 5, 6 and 7, at least, although additional Betas could follow.

“A few features are at risk,” Mozilla writes, enumerating the following items:

“- indexedDB unlikely to be included (spec is changing rapidly, security implications to be resolved)

- websockets likely to be included, but only as an experimental & prefixed feature possibly not matching spec (spec changing rapidly with new owner)

- some of the new UI features may not make the cut off

- priority is performance, UI upgrades and support for JetPack SDK.”

But at the same time Firefox 4.0 Beta 5 might not bring with it feature freeze for the browser. Mozilla could push Beta 5 as is, and introduce the feature freeze milestone a tad later in September 2010, but still by the middle of next month.

The browser vendor enumerated some features that are already confirmed for Firefox 4.0, the first already done, with the rest on track to completion:

“Feature complete Firefox 4

- Switch to Tab

- Extension Manager - Functionality there, lots of bugs to fix.

- Notification UI - Geo done, patches on follow up bugs.

- New Theme - Substantially done on Windows and Mac, Linux lagging.

- App Tabs - UI in place, functionality follow ups to get to feature complete

- TabCandy - Landed, but lots of follow up work to do on interactions, integration with other features.”

At the same time, there are also additional features deemed at risk, including Silent updates on Windows; Account Manager, Inspector and Web Console.

Firefox 4.0 Beta 4 for Windows is available for download here.

Firefox 4.0 Beta 4 for Mac OS X is available for download
here.

Firefox 4.0 Beta 4 for Linux is available for download
here.