SpatiaLite is an open source library intended to extend the SQLite core
to support fully fledged Spatial SQL capabilities. 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.

This requires proj, geos, and freexl.