A google might help..
http://en.wikipedia.org/wiki/PhysX
Novodex started up a long time ago, but it all based on C.. which I don't like.
It should be based on ASM, which is more efficient AND faster
and
http://en.wikipedia.org/wiki/Havok_(software)
is much the same thing..
So PhysX will be Nvidia based and Havok MSoft based (those annoying little toys like Xbox, playstation..etc
)
Oleg is spreading his wings... but either way it looks good.