Microsoft is closing down Skype, the video-calling service it bought for $8.5 billion in 2011 and which had helped spark a transformation in how people communicate online.

Skype, the Microsoft-owned service that popularized making calls over the internet, is hanging up for good. In May, Microsoft will shut down Skype, which it bought in 2011 for $8.5 billion in what at the time was the biggest acquisition in the tech titan’s history.