A few demos of the current non-optimized physics engine. The executables can be downloaded here as a zip. The source seems to be lost. All demos use c:/texture.bmp, which is included in the zip.
The scenes can generally be rotated using [space] and the sphere can be moved forward and backwards using [a] and [z]
In some of the examples you can see the sphere through the cloth. This is because I accidentally drew the sphere a little larger than its physical representation.
There are a number of different "demos" with different settings to demonstrate various points. They use constraints and over relaxation rather than ordinary springs.