DiDraw is a general purpose vector graphics drawing program. It is very easy to use even for novice users and still provides some advanced features. It is written in Java and runs on any platform supporting Java 1.3 or higher.
(Janat : Just Another Non-Artistic Tool) is a simple and user-friendly vectorial drawing software written in Java. It's particularity is to stores data inside a SQL database. This facts gives it the ability to run on a website, or store data on a remote
ThreeSpace is a 3D drawing program, or modeller if you will, primarily intended for visualizing and playing with mathematical functions. It allows you to superimpose these or otherwise alter objects in 3D using them.