Shrike

From ShWiki

Shrike is a demo framework for Sh. This boils down to several example shaders and a user interface to allow you playing around with the parameters they use and view various objects using those shaders.

You don't have to use (or even download) Shrike to use Sh, but it's a good place to see some of the things that have been done in Sh.

Why do some of the shaders in shrike not work, when others do?

Many of the shaders in Shrike exceed the instruction limits of some GPUs. Some use features only available in certain newer GPUs. This is the most common reason for a shader not to work.

You should also check that you have the shmedia package installed appropriately, and shrike knows where it is.