Hubbard, one of the co-founders of FreeBSD, launched in 1993, announced the news Monday on a FreeBSD mailing list, saying he'll shift his emphasis to Darwin, the open-source underpinnings of Apple's Mac OS X operating system.
"The FreeBSD product line has reached the stage where I feel comfortable taking a job that allows me to focus more on Darwin," Hubbard said in the posting. "Ever since Apple released the initial public beta, I've been following OS X's progress with great interest and an increasing desire to get involved with it somehow."
The move has the potential to increase the ties between the FreeBSD movement and Apple, helping Apple fulfill its hopes of capitalizing on the successes of the open-source movement in which programmers collaborate by openly sharing their programs' source code. And FreeBSD could benefit from some of Apple's work as well.
Hubbard said he hopes to foster such ties. "Darwin is substantially based on FreeBSD 3.2, and Apple certainly doesn't want the technology transfer to end there or to be strictly one-way. Part of my mandate will in fact be helping Apple to be an even better open-source citizen, increasing collaboration and strengthening relationships with FreeBSD and other open-source projects," he said.
Hubbard and Apple didn't immediately respond to requests for comment. However, in a note posted to an Apple mailing list, Core OS Engineering Director Brett Halle said Hubbard will be manager of BSD technologies at Apple.
"For his 'day job' at Apple, he will be responsible for leveraging BSD technology as part of Mac OS X as well as managing Darwin releases and Apple's partnership with the open-source community," Halle said.
Hubbard said he'll work to see that what he learns at Apple about software, such as user interface design, is applied to FreeBSD. And he hopes there will be cooperation between Apple and FreeBSD on subjects such as support for Universal Serial Bus and Firewire, two methods for plugging peripherals such as digital cameras into computers.
OS X includes proprietary higher-level software, such as Apple's Aqua user interface, that runs on top of the Darwin open-source foundation. Software called the Mach microkernel is at the deepest level of Darwin, with higher-level operating software from FreeBSD. Apple hopes Darwin will eventually be used more broadly than just with Macintosh computers using the Power PC chip.
Hubbard had been an employee at Wind River Systems since April. Wind River--which specializes in operating systems for all sorts of devices, such as routers or slot machines--hired Hubbard when it acquired the software assets of Hubbard's former employer, Berkeley Software Design, and pledged to contribute to the FreeBSD operating system.
Apple began installing OS X on its computers in May, though the earlier Mac OS 9 will still be the default that users see when the system is turned on. OS X is the first fundamental overhaul of the Mac's operating system since it was introduced in 1984.