Microsoft is taking the bubble wrap off its challenge to startup Slack’s white-hot workplace-messaging software, officially launching Microsoft Teams.

Businesses that use Microsoft’s Office 365 web-based productivity suite will see the new application appear starting Tuesday, the company says.

The Redmond company’s would-be Slack killer, built in the last two years, enters a more crowded market than when it was introduced in a preview version a few months ago.

Google has come calling. Microsoft’s nemesis has redesigned its Hangouts chat app with Slack-like features, unveiling the new concept at a company event last week. Facebook is also in the midst of a push to sell workplace collaboration tools.

At stake is the fast-changing realm of business communication, which, in addition to staples like email, has come to include digital messaging services and voice and video calls often handled over the internet instead of using telephone infrastructure.

Research firm Gartner estimates that businesses worldwide will spend $5.1 billion on web conferencing, collaboration and social tools in 2017.

Microsoft Teams, like Slack, allows users to set up running chat rooms with individuals or groups of colleagues, silo conversations in expandable threads, and share files.

Microsoft’s Office, a dominant software brand among information workers, is under attack from companies like Slack that take aim at a single area of workplace tools, as well as from broad assaults by the likes of Google and Amazon.

Google is working to leverage its dominant position with a generation of internet users to build a brand for its business apps, redoubling its efforts to sell the G-Suite productivity platform.

Amazon, meanwhile, is trying to expand its reach from developer tools to workplace applications, a portfolio that has come to include email, calendars and workplace communications tools.

Microsoft has tried to hold its ground by packing Office 365 with new features, some of which, like Teams, come at…