"As recently proposed, the version number of the Shiretoko project will be changed to Firefox 3.5 before the upcoming fourth beta release," said Mike Beltzner, Mozilla's director of Firefox, in a brief entry to the company's developer blog.
The name change has been under discussion for several weeks, prompted in part by calls from developers who thought that the "3.1" moniker didn't properly reflect the amount of new features and changes from last June's Firefox 3.0.
"The increase in scope represented by TraceMonkey and Private Browsing, plus the sheer volume of work that's gone into everything from video and layout to Places and the plug-in service make it a larger increment than we believe is reasonable to label '.1,'" Mike Shaver, Mozilla's vice president of engineering, said in a message to a company forum last week. "[Firefox] 3.5 will help set expectations better about the amount of awesome that's packed into Shiretoko."
"Shiretoko" is Mozilla's code name for Firefox 3.1, now Firefox 3.5.
Shaver also spelled out another potential benefit of the name change. "We expect uptake help from that as well," he said.
Mozilla will officially swap version numbers when it releases the fourth beta of the still-under-construction browser. Beta 4 is currently scheduled to ship April 14.
Mozilla originally named the next edition "3.1" to reflect the faster-paced development it planned for the upgrade. But those plans were disrupted last year by delays to add more features -- the TraceMonkey engine for one, a new privacy mode for another -- and build in more testing time.
Shaver said that the new name didn't mean Mozilla is now adding more to what was already in Firefox. "It's important to note that 3.5 represents a better labeling of our current scope, and not an indication that we intend to significantly increase this release's scope any further," he said.
The last version named Firefox 3.1 will be Beta 3, which is now slated to release Thursday.