Slony-I replication system for PostgreSQL

Slony-I is a "master to multiple slaves" replication system for PostgreSQL supporting cascading and slave promotion. Key features of Slony-I include:

 - Slony-I can replicate data between different PostgreSQL major versions
 - Slony-I can replicate data between different hardware or operating systems
 - Slony-I allows you to only replicate some of the tables to slave
 - Slony-I allows you to replicate some tables to one slave and other tables to another slave
 - Slony-I allows different database servers to be the origin(master) for different tables