CLucene is a high-performance, scalable, cross platform, full-featured,
open-source indexing and searching API. It is written in C++.

CLucene is a port of the very popular Java Lucene text search engine API.
Specifically, CLucene is the guts of a search engine, the hard stuff.
You write the easy stuff, the UI and the process of selecting and parsing your
data files to pump them into the search engine yourself.

CLucene aims to be a good alternative to Java Lucene when performance really
matters or if you want to stick to good old C++.

Homepage:
https://clucene.sourceforge.net/index.php/Main_Page
