This is a Tcl/Tk script that displays current database connections, and allows you to view the currently executing query, cancel the query, or terminate the session. You can also start/stop the postmaster.
The pgmonitorproject is a PostgreSQL Community project that is a part of the pgFoundry.
The pgFoundry page for the project is at http://pgfoundry.org/projects/pgmonitor, where you can find downloads, documentation, bug reports, mailing lists, and a whole lot more.
