PostgreSQL conferences
PostgreSQL is a relational open source database that can now easily rival major licensed database platforms such as Oracle and Microsoft SQL Server. More about Postgres is described in this blog: An expert’s view of PostgreSQL.
PostgreSQL is not developed or managed by a single company, but relies on a global community of developers and DBAs. The advantage for the user: no large, complicated (and expensive) licensing structures, and for those who want one: a worldwide network of committed IT professionals who put their heart and soul into optimizing database software. You can read more about open source community here.