Postgres R is an extension to the relational database system Postgres, providing efficient, fast and consistent database replication for clusters. It is designed to be as transparent as possible to the client, stable and secure by default.The primary use of Postgres R is to build loadbalancing and highavailability database systems on commodity hardware. Furthermore, due to the flexible architecture of Postgres R it is easily possible to extend or adjust the replication process to many different means. Compared to common single node database systems, a PostgresR cluster is more reliable and scales better while being cheaper and more flexible.

Website: http://www.postgres-r.org/