Mozilla developers have just released a brand new edition of Thunderbird email client.

This is a major update as Mozilla has handed over development to the open source community. They are going to focus on the Firefox web browser from now on.

Thunderbird 15 features an updated user interface to match that of newer editions of Firefox.

It also now features an inbuilt chat client that is compatible with Facebook, Gtalk, IRC, Twitter, and any XMPP network.

The search box can now search through the web, emails and even chat logs. Thunderbird also support Do Not Track for web searches conducted from inside the app.

Another cool feature is integrated support for Ubuntu One. YouSendIt is also supported. These services can be used to mail large files as links instead of attachments.

Mozilla spoke about this release:

As you can see integration is the word that best describes this new Thunderbird: integrated Chat, Mozilla newest user interface design integration, integrated email and chat search, integrated Do not track option for Search the web, new integrated Filelink partners with Ubuntu One.