Ingres is a feature rich and robust database (RDBMS) that's free to use, modify, and redistribute. Support is available for a reasonable price if you need it. Ingres supports many programming languages, including Python, Ruby, Java, Perl, C/C++, and more. Ingres has a bit of a learning curve, but once mastered is extremely powerful and highly tunable. It is also very stable and reliable. Ingres is one of a fairly small number of databases providing excellent geospatial features including data types and functions compliant with the Open Geospatial Consortium (OGC) Simple Feature Specification (SFS) for SQL.