Off The Record messaging is available on Linux and Windows and Mac

First install the software if you do not already have it

Windows

Download and install Pidgin:

http://www.pidgin.im/download/

Download and install the Off The Record Messaging

http://www.cypherpunks.ca/otr

Mac

http://adium.im/ (client comes with OTR built in)

Ubuntu or Debian Linux

In a terminal:

sudo apt-get install pidgin-otr

or System -> Administration -> Synaptic Package Manager, search for and install pidgin-otr

You can add all your AIM, MSN and GTalk accounts in this single application.

For additional privacy, use our Jabber server:

Adding a Rayservers Jabber Server Account

 

Enable Off The Record Messaging Plugin in Tools -> Plugins