Today Mozilla have announced it will delay Firefox 4 until 2011. The decision is after several weeks of no progress on Firefox 4 Beta 7 - which had a date to ship in September but missed it as they hit several bugs in the release.

Director of Firefox, Mike Beltzner said "Completing this work [on Firefox 4] is taking longer than initial estimates indicated as we track down regressions and sources of instability."

Beltzner said Mozilla could not push Firefox 4 out in November - and December "is a bad time to release a product" he said. Development for Firefox 4 has not slowed down, even with the delayed launch - "The user interface changes are converging, the graphics and layout features are wrapping up, and recently the JavaScript engine was dramatically improved." he added.

Firefox 4 is now slated for a release candidate status sometime early 2011.