This is an apt repository.

Please take care that the stable release of pgAdmin3 for debian/unstable is
now available directly from Debian mirrors. Have a look to:
http://www.debian.org and http://packages.debian.org/pgadmin3

For a complete download and installation instruction please refer
to: http://www.pgadmin.org/pgadmin3/download.php
On this page, you will also find mirrors near to you.

Feel free to report any problem to pgadmin-hackers list (<pgadmin-hackers@postgresql.org>).
Thanks!

The pgAdmin Project.