Firefox maker Mozilla has decided to keep the Thunderbird email client, so long as the project can prove its ability to operate independently and not be a burden on Firefox development.
For now at least the Mozilla Foundation, parent of Firefox maker Mozilla Corporation, will be Thunderbird's "legal, fiscal and cultural home".
However, the foundation has the option to pull the plug with six months' notice if the Thunderbird project does not make "meaningful progress in short order" in creating technical infrastructure that's independent of Mozilla Corporation's. The decision was announced on Mozilla's Thunderbird blog yesterday.
The 13-year-old Thunderbird never got close to Firefox's popularity. However, the email client, which is tied to Mozilla's Gecko engine, still has 25 million users. Mozilla stopped throwing resources at the project in 2012, by which time most people had opted for web mail.
This week's decision follows a review last year that explored new homes for Thunderbird at the Software Freedom Conservancy or the Document Foundation, the developers of LibreOffice, as well as a third option to establish an independent Thunderbird Foundation.
Mozilla Corporation and Mozilla Foundation executive chairwoman Mitchell Baker in late 2015 flagged the organization's desire to "disentangle" Thunderbird's and Mozilla's shared infrastructure. She didn't believe Thunderbird had the "industry-wide impact" that Firefox can have.
The separation plan was announced amid Mozilla's now-dead plan for Firefox OS to do for mobile what Firefox did for the web in offering an alternative to Android and iOS. Still, until Thunderbird could feasibly separate, Mozilla agreed to help the project accept donations and distribute funds as a fiscal sponsor.
Mozilla's fiscal sponsorship of Thunderbird continued during last year's review, while the Thunderbird project kicked off a fund-raising campaign that delivered a strong enough revenue steam to migrate from Mozilla's infrastructure as well as hire staff, according to Philipp Kewisch, a member of the Thunderbird Council.
"We were able to establish a financial home at the Mozilla Foundation. We are successfully collecting donations from our users, and the first steps of migrating infrastructure have been taken," he writes.
For example, Thunderbird is moving to its own domain, thunderbird.net and already has in place its own independent service, ISPDB, for auto-configuring users' email accounts.
Kewisch notes there are still "pain points" regarding product development that affect both Thunderbird and Firefox, but the council felt that moving to another organization wouldn't resolve them.
"In many ways, there is more need for independent and secure email than ever. As long as Thunderbird doesn't slow down the progress of Firefox, there seems to be no significant obstacles for continued co-existence," wrote Kewisch.
The catch for Thunderbird is that it's very dependent on Mozilla for Gecko, the Firefox browser engine that Mozilla eventually plans to replace with a newer Rust-based rendering engine called Servo, alongside technologies being developed in Mozilla's Quantum project.
Kewisch said the Thunderbird project hopes to be independent of Gecko in the long term, but in the mean time needs to stay close to Mozilla to help it work through Gecko-driven incompatibilities.
"Thunderbird will remain a Gecko-based application at least in the midterm, but many of the technologies Thunderbird relies on in that platform will one day no longer be supported. The long-term plan is to migrate our code to web technologies, but this will take time, staff, and planning," wrote Kewisch.
Read more about Firefox and Thunderbird