Jaspa
Spatial extension for relational database system. Follows OGC standars
Jaspa is a spatial extension for relational database systems, implements the OpenGIS Simple Features for SQL and partially the SQL/MM standard. Currently supports PostgreSQL and H2 as the RDBMS backends.
Jaspa brings around 200 spatial functions to relational database systems that support a full set of java store procedures. The first version of Jaspa was released in July 2010.
Jaspa has a similar functionality as PostGIS 1.5, supporting spatial operators and predicates, arrays of geometries, spatial aggregates, etc. Jaspa is written in java and is easy to extend using java stored procedures. This project is licensed under the GNU GPL.