Verity’s Ultraseek, a search engine, is now available for download and free trial. This is the tool we used at ASHA when I was working there. Excellent ability to tune results and the interface can be customized relatively easily using Python and HTML (although the templates were rather incomprehensible spaghetti code, which is hard to do with Python, normally). Hopefully the spaghetti issue was improved with the latest release.
Spotted via SearchTools.
C. David Gammel, CAE 
Good find. We have a couple clients that use this. You are spot on with the fact that it produces some pretty gnarly output. However, the search results are actually surprisingly good.
The one problem that we and our clients have had are the support and sales people are very tough to get in touch with.
Bum link, unfortunately.
Here’s the free trial download:
http://downloadcenter.ultraseek.com/dlc/ultraseek-docs.do
Thanks for the updated link, Zach. The original post is almost two years old!
I’ve really got to look at those dates. Have been getting a host of old posts from your blog coming into my reader. Not sure what that’s all about – bloglines or wp??