Curious as it sounds, Microsoft's open source lab has published an article on how to install and configure PostgreSQL on a Windows Server system.  This is very interesting, considering how PostgreSQL can be considered a competitor to Microsoft's own SQL Server 2005.

For those of you not familiar with PostgreSQL, it is an open-source, industrial-strength relational database with most of the features you'd find in a mature database server.  It has triggers, stored procedures and views, and can handle a variety of stored procedure languages, including Java, PHP and Ruby.  On the client side, PostgreSQL ships with both OLEDB and a .NET data providers.  One of the fascinating features of PostgreSQL is its ability to have inherited tables.  I can see where this could dovetail with OR mappings for subclasses.