I recently came across Superficies, a very nice tool for exploring surfaces and differential geometry concepts that I wanted to share. Here’s a link to its english manual that will give you an idea of the program’s features.
This is GPLed software written in Delphi and although binaries are only available for Windows I had no problem running it under Linux using Wine.
Superficies is a very good math software, however,it is
better if it is added with two projections:perspective and
parallel.