Configuring Pidgin for Facebook.

1. Open Pidgin.

2. Click on Accounts –> Manage Accounts –> Add window of Pidgin.

3. Fill the following details under Basics tab:
      -Protocol: XMPP
      -Username: enter your Facebook username without the facebook.com part.
      -Domain: chat.facebook.com
      -Password: Enter your Facebook account password.
      -Tick the remember password option if you want to auto login each time you start Pidgin.
     
4. Click on the Advanced tab, and uncheck the “Require SSL/TLS” box.  Be sure that:
      -Connect port: 5222..

5. Click Add to finish the configuration process.

Now start chatting happily without opening Facebook in browser.