According to CNBC, Slack plans to integrate Microsoft Teams calling features into its workplace collaboration app. Slack CEO Stewart Butterfield shared the plan during an analyst call. "We're working on Teams integrations for calling features," he said.

Adding support for Teams makes a lot of sense both because of the current situation and the fact that you can already use Microsoft services like OneDrive, Outlook and SharePoint directly within Slack. Butterfield didn't say when the calling feature will launch, nor exactly how it will work. That said, when the company added support for Office 365 apps last year, it did so using publically available APIs. At the moment, however, it's hard to say whether this is a sign of the two famously competitive companies coming closer together.