We are looking for a new search engine for Slashdot. Right now we use live searching in MySQL, which, well, sucks. I've been told to look into Plucene and Swish-e. Any other suggestions, or comments about those?
Plucene looks like a great, flexible, system, though I am concerned about performance and scalability (those are concerns with any system, but Simon says Plucene is "much slower" than its cousin Lucene, and I can find no info on scalability). I am beginning to look into Swish-e now, and have no comments about it yet.