The CEO of Mozilla Foundation's new Mobile Messaging subsidiary said the company is focusing its attention on producing the next version of its open-source email tool, Thunderbird 3.0.

David Ascher, CEO of the just-named Mozilla Messaging, said that the company's short-range goal is to have Thunderbird 3.0 in final form by the end of 2008, although the exact timing will depend on, among other things, the number of volunteers who flock to the project.

Claiming that "email is broken", Ascher said that Thunderbird 3.0 would build on the already-available Version 2.0 but add features such as calendaring, better and faster search, and a wide range of user-interface and usability improvements.

Mozilla won't be starting from scratch or working alone. The calendar addition, for example, will be based on the Lightning extension, which is currently at Version 0.7, and it will integrate scheduling and tasks with Thunderbird. Lightning was last updated in October 2007.

On search, Mozilla may collaborate with Qualcomm, owner of Eudora, a long-established proprietary email program that was abandoned in 2006. Qualcomm will produce a new Eudora based on Thunderbird's open-source code, said Ascher. But it may make sense for the two companies to work together on small-scale projects, like search, that both could share.

Mozilla Messaging arises from decisions made last July, when Mozilla - then the only for-profit subsidiary of the non-profit Mozilla Foundation - stunned Thunderbird users by announcing that it would sever ties with email development. In explaining the decision, then-CEO Mitchell Baker said that Mozilla's first priority is Firefox. "Mozilla doesn't focus on Thunderbird as much as we do browsing and Firefox, and we don't expect this to change in the foreseeable future," she said at the time.

Thunderbird, she added, should be cut loose "to determine its own destiny".

By September, Mozilla had seeded the new venture with $3m in start-up funds, and Ascher had been tapped to head the spin-off, dubbed 'MailCo' at the time for lack of a real name.

When Mozilla booted Thunderbird, users worried that the departure of the software's only two paid developers meant the client was doomed; neither chose to stay when the program was spun from Mozilla. Ascher said those fears had proved unfounded. "It wasn't hard to recruit," he said. "People were excited about the opportunity to work as part of a Mozilla [Foundation] project." A "handful" of developers are on the payroll, Ascher said, but like its Mozilla Corp sibling, Mozilla Messaging will heavily rely on unpaid programmers, testers and designers.

"The challenge is how do we evolve the platform?" said Ascher. In the long term, he said, Mozilla Messaging wants to beef up Thunderbird's back-end architecture and its development tools. In a long post that Ascher wrote for his personal blog, he noted that "Thunderbird hasn't had the resources devoted to it that Firefox has, and it's time to catch up, so that we can implement many of the features we have planned."

One thing not at the forefront of Messaging's corporate mind, according to Ascher, is how to pay the bills. The $3m from Mozilla gives the new venture breathing room. "[A revenue stream] isn't a huge priority right now," he said. "We want to make the best product possible, and then we'll think about a revenue model on top of that." Ascher declined to give a deadline at which point Mozilla Messaging will have to be self-supporting, saying, "There's not a real sharp deadline there."

Mozilla, which posted revenue of nearly $67m for 2006, the last year for which figures are available, makes the bulk of its income from the deal it struck with Google that assigned the search giant's engine as Firefox's default and from click-throughs on ads placed on the ensuing search results pages. It's unclear if Thunderbird could tap into the same stream.

Money will at some point become important to the new spin-off, however. Last October, Mozilla CEO Mitchell Baker remained vague about whether the company would continue to support the mail project. "We would like the new mail company to have its own revenue source rather than it continuing to come out of Firefox," she said then. "It's our hope that it finds other sources of revenue. But do we expect that it would be 100 percent? Not necessarily. Will we fund it for a while? Absolutely."

In a blog post of her own Tuesday, Baker - who is no longer CEO but retained her position as chairman of the Mozilla Foundation board - urged Messaging to get cranking. "I am exceedingly eager to stop thinking so much about how to organise the Thunderbird/mail effort and to start seeing all that energy go to improving our product. That day has come," Baker wrote.