CASA is a special-purpose system for computational algebra and constructive algebraic geometry. It computes with algebraic curves and surfaces and the corresponding ideal theoretic concepts.
Citation:
R.Hemmecke, E.Hillgarter, F.Winkler, "CASA", in "Handbook of Computer Algebra: Foundations, Applications, Systems", J.Grabmeier, E.Kaltofen, V.Weispfenning (eds.), 356-359, Springer-Verlag (2003)