You can get it free of charge by anonymous ftp on ftp-sop.inria.fr, hephaistos/Jpdraw directory
download xjpdraw, SUN or PC version : choose the wanted xjpdraw_.. version (xjpdraw_solaris for Sun, the other for Linux) and download all the other files in the directory
Here is an example you can program in a few minutes: it's the Connoly surface. Consider two fixed spheres (in thick lines) on which roll a sphere (represented in four differents positions and in thin lines). The surface is the trace of this sphere on the fixed spheres when its radius change.
And here is an example of drawing using the mouse (it's the logo of my diving club..and it's been created only for debugging the program!)
Current release: 4.4