Sphinx is a full-text search engine, distributed under GPL version 2.
Commercial licensing (eg. for embedded use) is also available upon request.

Generally, it's a standalone search engine, meant to provide fast,
size-efficient and relevant full-text search functions to other applications.
Sphinx was specially designed to integrate well with SQL databases and
scripting languages.

Currently built-in data source drivers support fetching data either via direct
connection to MySQL, or PostgreSQL, or from a pipe in a custom XML format.
Adding new drivers (eg. to natively support some other DBMSes) is designed to
be as easy as possible.

Search API is natively ported to PHP, Python, Perl, Ruby, Java, and also
available as a pluggable MySQL storage engine. API is very lightweight so
porting it to new language is known to take a few hours.

As for the name, Sphinx is an acronym which is officially decoded as SQL Phrase
Index. Yes, I know about CMU's Sphinx project.

1. build dependencies:
   1. postgresql-devel
   2. libstemmer-devel
   3. libexpat-devel
   4. rpm-build-ubt
   5. libssl-devel
   6. libunixODBC-devel
   7. zlib-devel
   8. gcc-c++
   9. libmysqlclient-devel