If we want to find a free alternative to Microsoft Lync, or just a light-weighted messenger application that does not require administrator priviledges to be installed, we can use Pidgin. Pidgin is a free open-source multi-protocol instant messenger that in combination with its plugin from SIPE project implements the extended SIP protocol used by Lync Servers.
Following these steps you will be able to connect to Lync Server networks, using Pidgin in this case.
1. Download Pidgin
You can download Pidgin from this link:
2. Install Pidgin
Double-click on the downloaded file and follow the instructions.
3. Download SIPE Project plugin
You can download Pidgin from this address: http://sourceforge.net/projects/sipe/files/
Click on the link next to “Looking for the latest version?”
4. Install SIPE Project plugin
Double-click on the downloaded file and follow the instructions.
5. Configure account
Open Pidgin.Go to Menu bar > Accounts > Manage Accounts or press Ctrl+A.
Click on “Add…” button.
In the Protocol dropdown list, select “Office Communicator”.
Enter Username, Login and Password, and click on “Add” button.
You can combine your Office Communicator accounts with accounts of different protocols or service providers.
Your Office Communicator Instant Messaging account will be configured! It is possible that you need to restart program or reboot to obtain full functionality.