Giac/Xcas is a free computer algebra system for Windows, Mac OS X and Linux/Unix (license GPL3, for commercial dual-license contact us). Giac is a free (GPL) C++ library, it is the computation kernel, it may be used inside other C++ programs. Giac/Xcas has a compatibility mode for people used to the Maple or Mupad CAS as well as for users of TI calculators (TI89, Voyage 200, TI Nspire CAS)