At an event in New York City introduced by Microsoft CEO Satya Nadella, the company introduced Microsoft Teams—a new chat service for groups that's the closest thing it's offered to enterprise-software phenom Slack.
Teams includes a lot of the stuff you'd expect: public and private groups, GIFs and emojis, bots, and integrations with other workplace tools. Thanks to Skype, it has voice calls (already available in Slack) and video calls (on their way). It also offers threaded discussions, which keep related conversations together and might make it easier to scan the back-and-forth than unthreaded ones.
Why would a company choose Teams over Slack, which is powerful, flexible, and way more engaging than the average business software? Well, Teams is part of Office 365, which means that it's not another service that Office users need to pay for and manage. It provides cross-app Microsoftian experiences such as the ability to work with Word files and OneNote jottings inside Teams, and the ability to manage Teams in the Office 365 dashboard.
Teams is currently available as a customer preview; Microsoft plans to roll it out as part of Office 365's Enterprise and Small Business versions in the first quarter of 2017.