Not necessarily related to python Web Crawlers

[disappearedng at gmail.com]

Hi
Does anyone here have a good recommendation for an open source crawler
that I could get my hands on? It doesn't have to be python based. I am
interested in learning how crawling works. I think python based
crawlers will ensure a high degree of flexibility but at the same time
I am also torn between looking for open source crawlers in python vs C
++ because the latter is much more efficient(or so I heard. I will be
crawling on very cheap hardware.)

I am definitely open to suggestions.

Thx