I'm looking for a good library that will integrate stiff ODEs in Python. The issue is, scipy's odeint gives me good solutions sometimes, but the slightest change in the initial conditions causes it to fall down and give up. The same problem is solved quite happily by MATLAB's stiff solvers (ode15s and ode23s), but I can't use it (even from Python, because none of the Python bindings for the MATLAB C API implement callbacks, and I need to pass …