DocFetcher is an Open Source desktop search application: It allows you to search the contents of files on your computer. — You can think of it as Google for your local files. The application runs on Windows, Linux and Mac OS X.
Nucular Archiving System for creating full text indices for fielded data. Python API, web, and command line interfaces. Fast. Very light weight. Concurrent read/writes with no possible locking issues. No server process. Proximity. Facets. Funny name.