PMON 2000 is a firmware that was orginally developed by swedish company called Opsycon, but the copyright also mention Rtmx Inc and ipUnplugged AB. The code is licensed under a four-clause BSD licence.
This firmware doesn't to appear to be supported anymore, and the source code is not freely available on the Internet.
This firmware was used at least in evaluation boards from Momentum, like the Jaguar ATX.
Quite the contrary!
PMON2000 is still alive, maintained and developed. More info is available at www.pmon2000.com. Regretfully the website has not been updated for some time as develoment of the PMON2000/SDK have taken up all time.
Source *shold* be available from anoncvs.pmon2000.com.