Slack accuses Microsoft of illegally crushing competition

Microsoft is undeniably one of the Big Tech elite, given its size, wealth and stock market value. But the software giant has stood apart from Google, Facebook, Amazon and Apple in one important respect: Microsoft, once the bully of the tech world, has escaped antitrust scrutiny so far.

Now Slack Technologies, whose popular chat and collaboration software has become embedded in the daily routines of millions of workers at thousands of companies, is hoping to change that.

Slack said Wednesday that it had filed a complaint against Microsoft with the European Commission, accusing the tech giant of using its market power to try to crush the upstart rival.