Plenty of group chats existed, but they weren’t easy to setup or use. Sure, if you had a whole team of nothing but software engineers, an IRC server was, and st

Plenty of group chats existed, but they weren’t easy to setup or use. Sure, if you had a whole team of nothing but software engineers, an IRC server was, and still is, a perfect solution. A completely non-technical company has no chance of setting that up. Slack made IRC that is friendly both for admins and users. They also added lots of modern features like mobile apps, notifications, embeds, etc. It didn’t solve a problem that hadn’t been solved. It’s just that all the existin solutions were quite stale. They provided an up to date solution to replace the old regime.