Sphinx is one of the best open-source alternative to replace MySQLs full text indices. This is not only because of its superior speed and smaller resource usage, but also because it provides extended features for full text searching, which are not available on MySQL FTS indices.
The talk will do a quick exploration on the syntax used for creating fulltext queries. Sphinx offers text matching operators like proximity, qourum, strict order operators as well as some special operators like SENTENCE,PARAGRAPH,ZONE. In Sphinx it's possible to choose between several built-in rankers, but also offers users a way to build custom ranking expressions with the expression ranker. Currently there are over 20 metrics that can be used to build a custom ranking expression. Also Sphinx comes with a SQL dialect for communication, which makes an easy transition from a FTS MySQL query to a Sphinx query.