Mozilla has spun off its Thunderbird email client into a new for-profit subsidiary and seeded the unnamed company with $3 million in start-up money.

The move is identical to the one made by the umbrella Mozilla Foundation in 2005 when it created Mozilla to manage Firefox. "The new organisation doesn't have a name yet, so I'll call it MailCo here," said Mozilla CEO Mitchell Baker on her blog Monday night. "Technically, it will be a wholly-owned subsidiary of the Mozilla Foundation, just like the Mozilla Corporation."

MailCo is the result of internal talks and public discussion about the future of Thunderbird that began in July. Then, Baker, who also chairs the Foundation, said that because Firefox was Mozilla's first priority, it had to divest itself of Thunderbird. Among the options she outlined: Creating a new non-profit organisation similar to the Mozilla Foundation to focus on the email program; building a new subsidiary of the foundation just for Thunderbird; and releasing Thunderbird into the wild as a community-only project.

Scott MacGregor and David Bienvenu, the two Mozilla employees who headed Thunderbird development efforts, voted for the third option. Today, however, Mozilla chose the second.

Most Thunderbird users blasted Baker and Mozilla. for wanting to ditch the email program, which competes with Microsoft's Outlook and IBM's Notes, as well as with Web-based email services such as Windows Live Mail, Yahoo Mail, and Google's Gmail.

The new company will focus on developing communications software based on the current Thunderbird product, its code base and its brand. The goal is to create a community of developers, similar to the one already in place for Firefox, that's dedicated to working on Thunderbird and associated products. "We can spark the same kind of excitement and energy level and innovation [as with Firefox] in the email/communications space," Baker said.

Among MailCo's out-the-gate goals, said Baker, are supporting existing Thunderbird users and creating "a better user experience for a range of Internet communications" that will explore how email should work with other technologies such as RSS, instant messaging, VoIP, and SMS.

David Ascher, the former chief technology officer and vice president of engineering at ActiveState Software, a Vancouver, British Columbia development tool maker, will lead the new company, said Baker in a statement. "David has been a respected member of the Mozilla community for many years and we're excited that he is joining Mozilla to lead this important effort."

Ascher, also the director of the Python Software Foundation, has led Komodo, a Mozilla-backed, open-source development environment project. Less than two weeks ago, ActiveState debuted its Open Komodo Project, which will switch many of the company's already-free development tools to open-source.

Mozilla was set to announce the new venture Tuesday morning, but moved up the news several hours to Monday night when Yahoo said earlier in the day that it would acquire Zimbra, a privately-held Web-based e-mail and collaboration provider, for $350 million.

It's unknown whether Mozilla's current in-house Thunderbird developers will continue with the new company. Baker hinted that they may not. In her blog, she explained that the $3 million in seed money for MailCo will "be spent mostly on building a small team of people who are passionate about email and Internet communications."

Neither Thunderbird developer Scott MacGregor, who started the project in February 2003, or his co-worker, David Bienvenu, responded to a request for comment.