Franklin Math is an open source Java symbolic computer algebra system (CAS), with similarities to commercial math packages such as MATLAB or Mathematica. It allows numeric and symbolic calculations, with built-in functions including plotting commands.
GiANT is a graphical interface for computer algebra systems (OS X/UNIX/Win). Currently GiANT lets the user work with number fields via KASH, but we aim to develop it into a GUI Library to run on top of any CAS and expose any of its functions.