pixel shader manuals

hi there

i want to get into vertex and pixel shader (which should run on both nividia and ati hardware if possible) programming with openGL. could someone please point me to

*) a good tutorial about shaders in openGL
*) a complete manual of all the commands that are available to shaders? (i seem to be unable to find anything like this)

i’d greatly appreciate any help!

thanks
hoshi55

For “all commands” look at http://oss.sgi.com/projects/ogl-sample/registry/
and read all extensions with _program or shader in the name.

Demos can be found at the usual developer site of the vendors.