Microsoft Communicator 13.1.3 for Mac is free to download from our software library. The latest version of the application can be downloaded for Mac OS X 10.5.8 or later. The unique identifier for this application's bundle is com.microsoft.Communicator. The application lies within Communication Tools, more precisely Texting & Video calls. The most popular versions among Microsoft Communicator for Mac users are 13.1 and 13.0. The actual developer of this free Mac application is Microsoft.
From the developer:
Microsoft Communicator for Mac 2011, the communications client for Macintosh computers, includes real-time audio calls, video calls, and new presence statuses to improve the way users find and connect with their coworkers.
*Calendar-based presence Communicator offers new presence statuses to more accurately reflect whether someone can communicate with you at that time.
You may want to check out more Mac applications, such as Microsoft Lync, Microsoft Remote Desktop or Microsoft Outlook, which might be related to Microsoft Communicator.