Indextank-simpleworker-static is a project mainly written in Ruby, it's free.
Example of how to create a search engine with IndexTank and SimpleWorker
Example of how to create a search engine with IndexTank and SimpleWorker.
Why this is interesting: you don't need a server
The html page loads the search results via javascript directly from the IndexTank Public API
The index is populated by a SimpleWorker instance which you can run at simpleworker.com
How to use this:
Just replace your SimpleWorker and IndexTank keys in both files. You'll need your public api url for index.html, and your private url and SimpleWorker keys in worker.rb