From: DeskNow Knowledge Base
http://www.desknow.com/kb/

How do I configure Pidgin with DeskNow?
http://www.desknow.com/kb/idx/8/203/article/

It is very easy to configure Pidgin with DeskNow.

Make sure that TCP ports 5222 (no encryption) and/or 5223 (SSL encryption) are open between the client and the DeskNow server.

Assuming that your DeskNow username is user@domain.com, add a new account of Protocol "XMPP". Fill in the form as shown below.