[Zope] Cataloging non-zope content?

I'm interested in the possibility of a zcatalog (or derived product) that can crawl and index remote URLs. That would allow my zope sites to search my non-zope sites. Has anybody set up something like this? The alternative I guess would be to use some other search engine for everything, and have an interface to that on my zope sites. --PW Paul Winkler "Welcome to Muppet Labs, where the future is made - today!"