Hipchat, Facebook's Workplace, and whatever Microsoft's service is are all competitors but I don't think any of them are serious. Hipchat is probably the bigge

Hipchat, Facebook's Workplace, and whatever Microsoft's service is are all competitors but I don't think any of them are serious. Hipchat is probably the biggest competitor, but that's because it was around before Slack. When there's a serious competitor in the space, then I'm sure they'll start caring. For now, I don't think anything else is close.