The increase in version number is proposed due to the sheer volume of work which makes Shiretoko feel like much more than a small, incremental improvement over Firefox 3: TraceMonkey, <video> tag and player support, improvements to user controls over data privacy, significant improvements in the web layout and rendering platform, and much more.

Under this proposal:

• Shiretoko would be released as Firefox 3.5,
• the upcoming third beta release would still carry the 3.1b3 version numbering,
• the following foruth beta will be numbered Firefox 3.5b4,
• “Minefield” builds from the trunk mozilla-central repository will be renumbered to 3.6a1pre until further notice – we will need to consider and decide on a version number for that release at a future date,
• the Gecko version numbering will not change, remain 1.9.1 on the mozilla-1.9.1 branch and 1.9.2 on the mozilla-central repository for the forseeable future.