Poodle is collection of ruby based “tools” which work collectively with Apache Solr to produce a simple intra-net search tool. It is similar to the Java based Nutch search tool - Although at present (and probably forever) nowhere near as rounded.
It comes with a ruby based crawler which indexes to Solr, and a rails application to display search results from the indexed content.
Here is an example screen shot of a search result for this site:
The code is on github