Next year I'm going to do my final project for graduation. I've been assigned to search and study some biomathematical models with bifurcation theory and numerical bifurcation analysis.
I'm thinking about use AUTO (http://indy.cs.concordia.ca/auto/) (as my professor suggested me) for this task but would like to know if there are another good/current choices I should take into account.
I'm relatively good at programming in Mathematica, Matlab, Maxima, Octave, Python, Fortran, C++, and FreeFem so programs or libraries are both welcome.
Thank you!

AUTO is a good standard choice; it's got a pretty steep learning curve though. If you do decide to use AUTO, it's definitely worthwhile to work through the tutorials. You could consider MatCont, which is a bit more user friendly, and has a natural Matlab embedding (which is good if you like Matlab). Either way, it's a good idea to invest time to learn how to use (at least one of) these programs, it's a valuable skill.
Especially since you've got an affinity with programming, I would suggest you use a specialised program (such as AUTO or MatCont), instead of using general purpose mathematical software. I think that, with your skills and experience, you'll get the hang of it fairly quickly.