Bucardo provides multi-master replication for PostgreSQL http://bucardo.org/ http://bucardo.org/ and is actively maintained, albiet written in Perl. The reaso

Bucardo provides multi-master replication for PostgreSQL http://bucardo.org/ http://bucardo.org/ and is actively maintained, albiet written in Perl. The reason most replication systems sit outside of PostgreSQL are there are many different use cases for replication and no one method is going to get it right enough to complicate the core code. There are efforts underway to create a common structure to base replication on so that projects like Bucardo, Slony and Londiste can more easily and reliably plug into the core database engine for replication.