SpatiaLite - Spatial SQL

SpatiaLite is an open source library intended to extend the SQLite core to support fully fledged Spatial SQL capabilities. SQLite is intrinsically simple and lightweight, It is a single lightweight library implementing the full SQL engine. SpatiaLite is smoothly integrated into SQLite to provide a complete and powerful Spatial DBMS (mostly OGC-SFS compliant). Using SQLite + SpatiaLite you can effectively deploy an alternative open source Spatial DBMS roughly equivalent to PostgreSQL + PostGIS.