VirtualPG is a loadable dynamic extension to both SQLite and SpatiaLite.

Its intended scope is supporting direct SQL access to PostgreSQL and 
PostGIS own tables, so to make any possible kind of data exchange 
between these two popular open source Spatial DBMSes as straightforward 
and simple as possible.

Note:  VirtualPG can access PostGIS Table which means that postgis is
an OPTIONAL REQUIRE.

VirtualPG is licensed under the MPL tri-license terms; you are free to 
choose the best-fit license among:

   the MPL   1.1
   the GPL  v2.0 or any subsequent version
   the LGPL v2.1 or any subsequent version