For a while, the two projects used different version numbers, but for now they are on the same level. The Thunderbird client now also shares the same version number with Firefox 31, which was launched today as well. There are some alternatives out there, at least on the Linux platform, but it looks like Mozilla Thunderbird is just dragging its feet. The advent of the Internet browsers and the increased functionality provided by services like Gmail, Yahoo, and Outlook has made this type of client almost redundant. In fact, it's been a very long time since any real work has been done on the client. They would only push important security updates, but the implementation of actual features has been left to the community, which didn't do a great job so far. The company announced a while ago that it was no longer actively developing the software. It's been a while since Thunderbird received any real improvements, but that's not exactly Mozilla's fault. The first version has been released in the Thunderbird 31.x branch, but unlike some of the previous updates, this one actually brings something interesting. Mozilla has officially released Thunderbird 31.0, an email and RSS client, for all the available platforms, and the developers have actually made a number of improvements to the application.

Download mozilla thunderbird version 31