[ODE] coulomb friction model?

[Graham Fyffe]

Hi all!  I'm trying to use a coulomb friction model for my own
simulation stuff.  I am in the middle of decyphering Baraff's paper
and website, where he prescribes using a modified Dantzig method of
sorts.  My question is, what algorithm does ODE use?  I've tried
parsing through the step.cpp file, but I can't extract the algorithm. 
There seem to be optimizations based on the two-body joints that mask
the true meaning to me.  I've read about the jacobians and matrices in
the joints how-to document as well, but it is very light on what
actually goes into the matrix in order to handle the "max force"
properties of friction.  I've also red Russ's articles on the subject
in the Games Programming Gems books, but again it is light on details
about how to construct the matrix.  Can anybody help me out?

BTW, I'm not using ODE for this project because the model is very
simple; I only care about angular velocities of some parts and the
rest of the system is totally fixed.  Also, ODE is unusable for it
because I have linear constraints involving up to 5 of the bodies,
whereas ODE only supports 2 :(

- Graham Fyffe