There's an introduction to PostgreSQL replication at
http://wiki.postgresql.org/wiki/Replication%2C_Clustering%2C_and_Connection_Pooling
and a work in progress to provide more up to date information about each
of them at http://wiki.postgresql.org/wiki/Clustering I'd suggest
starting with. Replication is a complicated topic, and you need to
carefully match the software used with your business goals. There is no
such thing as a generic replication package that works for all
situations. If you shared a bit more about what you're trying to
accomplish, you might get a more focused recommendations for where you
can find it.
--
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.com