ZD Net UK: Apple releases core of new open source OS

“The first version of the open source operating system core that
will be at the heart Apple’s new operating system OS X was released
in the US Wednesday.”

“Darwin 1.0 will constitute the core of Apple’s forthcoming
operating system called OS X and is partially based on the open
source Unix-like OS, BSD….”

Opening up its source code is likely to popularise Apple’s
OS X when it is released in the summer, but the company’s decision
to embrace the open source movement is not quite absolute.
does not plan to make all of the source code for the OS X server
available to open source programmers.”