= Recoll = 
is a personal full text search tool for Unix / Linux.
[http://www.lesbonscomptes.com/recoll/]

 * based on the very strong Xapian search engine library
 * powerful text extraction layer 
 * complete, yet easy to use
 * Qt graphical interface.
 * Recoll is free, open source, and licensed under the GPL.
 * last update 2011-11-26 (now 2011/12/06)

 = Xapian =
is an Open Source Search Engine Library
[http://xapian.org/]

 * released under the GPL
 * writing in C++
 * with bindings to allow use from Perl, Python, PHP, Java, Tcl, C#, Ruby and Lua (so far!)

 * latest stable version is 1.2.7, released on 2011-08-10.