It's a reasonably nice client, and available on every platform. It has easy integrations with basically everything, and non-developers can set them up on their

It's a reasonably nice client, and available on every platform. It has easy integrations with basically everything, and non-developers can set them up on their own. It has bouncer functionality built in - You don't miss messages. It can also archive them, and handle them in a corporate-compliant way without needing to speed a bunch of time setting that up manually. Because it's a central company and not IRC push-notifications are easy. Emoji are shared corporate wide, anyone can add them. It's a really nice out of the box experience. You can absolutely replicate it with enough setup and tweaking, but the free version of Slack will go a long way.