Crystal Space, Cal3d, Open Dynamics Engine

We currently use ODE for our physics at school...currently our physics is BROKEN and does NOT work!! But i don't think thats actually to do with ODE :)
I haven't worked with it much myself, but from my glancing experiences with it, it is quite good and accurate, the only major problem i've found with it is that it is a little to realistic for use with games. All collisions are completely elastic so if you run into a static object that can't move, you end up bouncing away, which isn't so good for a car crashing into a building. Basically this just means you have to do a little bit of extra funky stuff on top to try and dampen the reaction. Also, it does not offer dynamic collision detection (not sure if thats the correct phrase), by that i mean, it can't test if two objects will collide over a period of time, it can only test if two objects are currently colliding. I'm not sure if other physics engines offer this type of CD, but ODE doesn't. This has the unfortunate effect that for fast moving objects you need to do 10-20 physics updates per frame (at about 60fps) to avoid objects moving completely through each other and not registering a collision.
CYer, Blitz

for fast moving small objects (bullets), you shouldnt really use ODE, do a basic CD with line checks for bullets etc... or swept spheres for larger objects

Yeah, not talking about bullets or anything...talking about cars :)
And we're too lazy to write our own CD :P
CYer, Blitz

ODE should be fine for that, just run it at a fixed framerate (say 100fps), independent of your game tick -- depends on how fast your cars are moving tho ;)

Would ODE be alright for a sword fighting game? I'm thinking that swords move a lot slower than bullets.

probably not, swords, are long and thin, and move fast relative to their sizes :) --- tunnelling baby, yeah