|Windows, Linux, Mac OS X,
OS/2, eComStation, OpenSolaris
|MPL/GNU GPL/GNU LGPL
Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation.
Thunderbird aims to be a simple e-mail, newsgroup and news feed client. The vanilla version is not a personal information manager, although the Mozilla Lightning extension added PIM functionality.