Mozilla has shelved Firefox 4 and is now expected to release the open source Web browser early next year. Mozilla, which was working to release Firefox 4 this November, admitted that the browser was taking longer to finish than they anticipated.

In a blog post, the company said that it encountered delays in finishing the beta 7 version of the browser in spite of "strong progress" in development. The company also had to push back the release date due to the amount of preparations remaining before the software can be released.

In a blog post on the Mozilla developer Web site, Mike Beltzner, Firefox's product manager, said, "Completing this work is taking longer than initial estimates indicated as we track down regressions and sources of instability... As part of our commitment to beta users, we will not ship software before it is ready."

Beltzner adds that "beta milestones" of the browser would be released in December, with the final version expected to ship by early 2011. In spite of this, Beltzner said that the timetable is not set in stone.

"Please note that, as always, this schedule is subject to change based on feedback from users and community members."