Sphinx is an open source full text search server that is programmed with relevant search quality and integration simplicity.
Sphinx
allows flexible testing whereby its indexing features include full
support for SBCS and UTF-8 encodings, stopword removal and optional hit
position removal (hitless indexing); morphology and synonym processing
through word forms dictionaries and stemmers; exceptions and blended
characters; and many more.
Sphinx has an easy
application integration that is derived from 3 different APIs. It has a
native library for many programming languages, a pluggable storage
engine for MySQL and an application query that uses MySQL client library
and syntax.
Websites such as Craigslist, Living Social, MetaCafe and Groupon has adopted Sphinx for its searches.
Programming Language: C++
License: GPLv2 and commercial
Ranking of search results: Versatile
Indexing style: SQL database indexing and Non-SQL storage indexing."