Isn't Skype for Business Microsoft's old own Lync rebranded as Skype? [1] [2] It's seems it is about to become Microsoft Teams.

[1] https://en.wikipedia.org/wiki/Skype_for_Business

[2] https://www.microsoft.com/en-us/microsoft-365/blog/2014/11/1...

> In the first half of 2015, the next version of Lync will become Skype for Business with a new client experience, new server release and updates to the service in Office 365