Custom material nodes?

In 2.4, you could create “dynamic” (custom-coded) nodes; this seems to be lacking in 2.6, 2.7, etc.
Is there still a way to create custom nodes, and if so, could someone give me a short tutorial? Thanks!

Apologies for bump, I’m interested in this too.

http://wiki.blender.org/index.php/User:Phonybone/Python_Nodes I don’t know if this can help or if it is releated to 2.49 and older versions…
https://vimeo.com/90065481 this is cycles releated, but maybe similar method can be used in BGE
However, you can script a custom glsl material yourself…
Node groups make you able to make a node(actually a group, but that works like a node) that contains your own assigned features and shaders(look at this: https://www.youtube.com/watch?v=fOcHxcCPoyI)