Shell Search is an efficient file search program written in python. It is supported both on Windows operating systems as well as Linux. It has not been tested on mac, but it should still work properly.
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.