Tomorrow, the makers of Firefox will be launching the third version of Thunderbird, its open source and free email application that is produced out of Mozilla Messaging, which is a subsidiary of Mozilla devoted to producing innovation around communication and the internet. Thunderbird 3, which is available in 50 languages and is compatible with Windows, Mac OS X and Linux, has made more than 2,000 improvements and fixes to the new email client. Thunderbird 3 will be available to the public mid-day tomorrow here.