Firefox 4 is to arrive by the end of the year, with promises of a speedy new cut-down interface and HTML5 support.
In a presentation, Firefox director Mike Beltzner explained that Firefox 3.7 will be rolled into 3.64. Therefore, there will be no 3.7 arriving this summer, but 4.0 is expected to arrive by November, with a beta possible by June.
Beltzner said the major update will make Firefox faster, improve the interface, and help out developers - but his presentation was filled with caveats that anything and everything was subject to change before the final release.
Speed and user interface
As always, Mozilla is looking to make Firefox faster. But rather than focus only on speed benchmarks, it wants to make its browser feel quicker by tweaking the user experience.
"The simpler it looks, the faster it will seem," said Beltzner. "We're looking at making our interface faster just by changing the way it looks."
Firefox 4 will also introduce a new "switch to tab" feature, which alerts users that a page is already open - preventing multiple instances of the same tab being unwittingly opened.
Beltzer said users should expect to hear more about something called "Tab Candy", but that Mozilla wasn't sure if it would appear in Firefox 4 or later versions.
In addition, updates will run in the background, not at start up.
Other changes
Beltzner said Mozilla was also working on a new way of finding and managing add-ons, and hoped to offer more that could be installed without a restart.
Beltzner added that Mozilla is looking into how it should deal with third-party cookies too.
Developers
For developers, Mozilla is working on bringing HTML5 and CSS3 to Firefox 4, and is looking into making multi-touch and gesture recognition work in the browser. It also wants to include native multimedia - such as animation, video and audio playback - without plug-ins. Beltzner noted 3D was on the way as well, but said it may or may not arrive in Firefox 4.
Firefox 4 will include the new add-on development programme JetPack, as well as a new tool dubbed Web Inspector, which lets developers look at code in a console inspired by Quake. The new JavaScript extension JaegerMonkey will also arrive in Firefox 4.
Mozilla will release a 64-bit version of Firefox 4 for Windows and Mac OS X, Beltzner added.
Competition
Will the changes be enough to hold off rivals Google Chrome and Microsoft, which is set to unveil Internet Explorer 9?
"We've built the web ecosystem into the space we want it to be," said Beltzer, referencing the increasing level of competition in the browser market.
"We are in it to win it," he added.
