Can PhpDig spider only certain sites?
 

Lets say I want to create a search engine specific to GOLF. Is it possible for PhpDig to spider only golf related websites?

Also, how robust is the software? Will it handle mega-traffic?

PhpDig attempts to spider whatever you give it, so if you want a golf based search engine, then just feed PhpDig golf based links. For the latter questions, maybe join this discussion.