A good clipping algorithm

I have read up on a bunch of different culling algorithms (frustum, occlusion, etc.)and I can understand the concepts. Is there an example anywhere on an actual implementation? I can’t seem to find a good code example of the best way to use them.

Also I heard (somewhere) that basic viewport clipping is automatically done in some drivers. Is this true or just another entry into a wishlist?

[This message has been edited by SuperFly (edited 10-23-2000).]