pgAdmin III

http://www.pgadmin.org/

pgAdmin is the most popular and feature rich Open Source administration and development platform for PostgreSQL, the most advanced Open Source database in the world. The application may be used on Linux, FreeBSD, Solaris, Mac OSX and Windows platforms to manage PostgreSQL 7.3 and above running on any platform, as well as commercial and derived versions of PostgreSQL such as Postgres Plus Advanced Server and Greenplum database.