An anonymous reader writes "Recently Microsoft's open source software lab posted PostgreSQL on Windows: A Primer. Postgres is one of the longest running open source databases — it has been around for nearly 11 years. The powerful object-relational database is a direct competitor to other OSS databases, as well as Microsoft's SQL Server 2005. So why is Microsoft promoting it? I get Redmond's interest in boosting anything that runs on Windows as a platform. Is this simply a case of left-hand, right-hand, or is something deeper going on?"