The Mozilla Foundation has established a new subsidiary focused on developing its free, open-source Thunderbird email software.

Mozilla Messaging will initially focus on developing Thunderbird 3.0, which aims to improve several aspects of the software, including integrated calendaring, better search, as well as enhancements to the overall user experience.

The Mozilla Foundation is best known for creating the Firefox web browser, a potent rival to Microsoft's Internet Explorer. The organisation enjoys wide support in the open-source community because both Firefox and Thunderbird are based on the open-source development model.

Mozilla Messaging will continue using the open source model in work, maintaining a small product development team to work with contributors from around the world on Thunderbird software.

David Ascher is the CEO of Mozilla Messaging and sits on its board of directors, which also includes Christopher Beard, vice president and general manager of Mozilla Labs, and Marten Mickos, CEO of open source database vendor MySQL AB.

Mozilla Messaging is a wholly-owned subsidiary of the Mozilla Foundation.