ODE is a physics Library used in commercial games like
"Soeldner - Secret Wars", "BloodRayne 2", "Xpand Rally", "Hellforces",
"Amsterdam Taxi Madness", "ATV", "Elite Heli Squad", "Manhattan Chase", "Pedal
to the Medal", "Shanghai Street Racer" and "Taxi3". Also Open-Source libraries
like
the CrystalSpace engine (where an AmigaOS 4 port is since some time in the
works, with no release date announced) are using ODE.

Licence: You can choose between BSD and LGPL, whatever you prefer. This model
of
licencing enables both commercial companies and "strictly minded" opensource
people to use ODE. IMHO it is the best licence-model, as the past of ODE
proved.
Both OpenSource and Commercial people contributed
source-code to ODE (yes, source from commercial games was
contributed) in the past.

So what is "Physics Simulation" ? This is about the 100% (well, sort of :-) )
simulation of a realistic physics environment in computer games or demos. ODE
offers you such
a environment, and you can very easy model your physics environment and have
things happening...

Maybe someone would write a graphics demo using ODE ? :-)

And now, what is "Opcode". Opcode is a specific Collision-Library which is used
by the Trimesh-enabled version of ODE. Now in the "basic" version ODE simulates
RigidBodies
as "simplified" objects (cubes, spheres,...). For a game sometimes you need a
more exact simulation of the form.
A TriMesh basically can simulate ANY FORM. And Opcode is needed for the TriMesh
code of ODE. 

Both libraries will be compiled together, using config/user-settings you can
select if you want to use the Trimesh/Opcode or not.

Please note that I did not port all of the demo-programs, this archive only
includes the library itselves, one of the "official" demos, and one additional
demo. Both demos are ASCII-only and only interesting for developers. Actually
one of the demos gives a "FAIL" at one place, but this is probably related to
the demo-source, as the same FAIL happens on other platforms where I tried
(Linux, Windows) too.

Both the opcode/trimesh-including and the non-including version are available
precompiled for newlib in the lib-directory. The code should compile fine for
clib2 as well, though.