A not so good demo. But hey, it's my first.
D programming language and OpenGL were used to create it. This is not a real time capture, but a rendering.
You can get the code and the Linux binary from http://www.scene.org/file.php?file=%2Fparties%2F2007%2Faltparty07%2Fdemo%2Ffrequency_bush_by_reuna-final.tgz&fileinfo