Microsoft Teams

Have been using advanced chat capability Slack for a project.  Not overly impressed.  Impressed me because it was new, not because it had real value.  Now Microsoft is attempting something similar:

Review: Microsoft Teams tries to do Slack one better
Microsoft is now offering the beta of Teams, its new group communications tool, which promises a new level of productivity for Office.

While it's become the standard productivity suite for many businesses, Microsoft Office has lacked a tool specifically built for group communication and collaboration.

Enter Microsoft Teams, a cloud-based, chat-centric app for group communication and collaboration, which lets groups and subgroups create their own channels to work together using text chat, file sharing, calendaring, and voice and video chat. It's targeted squarely at Slack, which has become a well-known option for businesses that want to encourage workplace communication (and is, incidentally, something that Microsoft reportedly considered buying for $8 billion until CEO Satya Nadella nixed the idea). ... "