Previously known as Skype Teams, Microsoft has built a Web-based chat system.

Microsoft is holding an event in New York City on November 2 next week. It's an Office event, but beyond that, the company hasn't officially said what it's about.

Microsoft is also building a competitor to Slack, the Web-based IRC-like messaging app that has become the darling of millennial-infested newsrooms and software startups around the globe. It looked like it was originally to be called Skype Teams, but now the branding has switched, to simply being Microsoft Teams. Which isn't a bad name in and of itself, but if Microsoft wanted to use the Skype branding for all its communications products (it already renamed Lync to be Skype for Business) then the original name did make sense.

Putting two and two together, it's believed that the event next week will where Microsoft makes Teams official and properly unveils it to the world.

Leaked screenshots of Teams actually look rather good. The synergy between this kind of group chat program and other parts of Office 365 seems straightforward, leading many to suggest that Microsoft should simply buy the startup. But with a $4 billion valuation it always seemed rather expensive to buy, given the size of its user base and the faction of those users that are paying. Microsoft could build something for far less, and with tens of millions of Office 365 users could drum up many more customers almost overnight (though of course, there's a difference between including Teams in an Office 365 bundle, and having companies actually use it in earnest).