[Pyxl101]

As far as I'm aware Slack does not offer on-premise installs. (On-premise in this case could mean running in my own account at a cloud service provider) It's unfortunate because I'd love to adopt them as well at my current company, but it will be very difficult to achieve if the only option is to become yet another tenant of some large multi-tenant infrastructure.

Microsoft will quickly take over this market if they offer an easy-to-manage on-prem solution that's integrated with the company directory, as it seems they've done. Plenty of firms already have Exchange and ActiveDirectory and Skype for Business.