In 2006 the company of Open Firmware inventor Mitch Bradley, Firmworks, Inc, released their Open Firmware implementation under a BSD license. This code shares some code with SUN's OpenBOOT implementation. It supports the x86 architecture and runs, amongst others, as a LinuxBIOS payload. It is the firmware implementation on the OLPC.
The code can be browsed online with the ViewVC facility.
The repository is available through Subversion:
You can check it out as follows:
$ svn co svn://openbios.org/openfirmware/
if you want a specific revision:
$ svn co svn://openbios.org/openfirmware -r 35
If your company installed a firewall that blocks the svn port (3690) you can also check out using the webdav frontend:
$ svn co https://www.openbios.org/openfirmware-svn/ openfirmware