PQ Torus Knot
I added in GLSL Hacker (v0.6.4.1) the support of PQ Torus Knot based on this code sample and on this this article. A demo showing how to create a mesh PQ torus with GLSL Hacker can be found in the host_api/Mesh_PQTorusKnot/ folder of the code sample pack.
A thread in the forum is available here with a code snippet.
PQ torus is cool because playing with two numbers (P and Q), you can generate many different knots. Here are some screenshots for particular values of P and Q parameters: