“In many ways Firefox 3 is much more stable than anything else out there,” Mozilla Corp Vice President of Engineering Mike Schroepfer said in an interview.

Additions boost security and allow users to run Web sites when they are not connected to the Internet. Mozilla also says Firefox 3 uses less RAM than Firefox 2.

Engineers at Mozilla are still putting the finishing touches on the software and hope to release the final version of Firefox 3 by the end of June, Schroepfer said. A 5th round of changes, will involve “tuning the visual look and feel of the program” and further improving its stability,” Schroepfer said.