On Tuesday Mozilla released Firefox 7, the next release of the open source web browser. This comes exactly six weeks after the last release and is in line with their rapid release model. Usually users should get the update automatically. The email client Thunderbird got the version bump to seven as well.
The main improvement of Firefox 7 is the vastly improved memory management. According to developer Nicholas Nethercote, who was heavily involved in project MemShrink, Firefox 7 should use about 20-30% less memory, sometimes even 50% less. Memory usage should stay more steady over longer sessions and closing tabs should free up memory more quickly. This has been one of the main criticism when comparing the browser to Google Chrome.
On top of that, Firefox now uses a new rendering backend to speed up canvas operations on Windows platforms. Support of new web technologies has been added and improved. To help Mozilla to improve performance further, you can now opt in to submit anonymous performance data. Of course the usual stability and security improvements are included as well. For more details hit the release notes.
On the Thunderbird side of things, several bugs related to attachments have been squished. You can now also print a summary of multiple selected email messages. Thunderbird is always updated at the same time as Firefox as it uses the same underlying technology. A detailed list of changes can be found in the release notes.
When we look at market share numbers, we can observer a slight decline in Firefox installations over the last
months. On the other hand Chrome was able to expand its user base slightly. Due to strong sales of Apple products Safari gains a bit too.
Around the release of Firefox 6 it was also discussed to remove the version numbers altogether. There was strong opposition to this move which is why for the time being, version numbers are here to stay.
Mozilla also plans to offer an Extended Support Release (ESR) which is aimed at companies and organizations, who would have trouble certifying and operating the current rapid releases. The idea is that there will be two ESR releases yearly, which receive security-related updates for 42 weeks (i.e. 7 rapid release cycles). After 30 weeks the next ESR release appears, so there is always a 12 week overlap between supported releases. The updates should only incorporate security fixes and omit the added functionality that is added in the rapid releases tailored for consumers. For the email client Thunderbird, the model would be adopted likewise. Note that this is currently a proposal, so nothing is set in stone yet. More details can be found on Mozilla’s Enterprise wiki.