I use IRC, but come on. It offers <i>a lot</i> more than IRC right out of the box.<p>* File uploads<p>* Embedding portions of links (tweets, images)<p>* A very good search<p>* Multi-line posts<p>* Code-formatting, including multi-line posts, and also snippets.<p>* A mobile client that alerts you when someone mentions you.<p>* Scroll-back history when you sign on at any time.<p>* Syncing between multiple clients.<p>Yes, you could create a bot or modify an irc server to do this, and then find or write a client that will do all that stuff, and an irc bouncer can fill in for a lot of this.<p>But Slack does it <i>out of the box</i>. Zero extra work needed.<p>I like IRC, but if you claim that Slack doesn&#x27;t offer anything more than IRC, you&#x27;re either delusional or using an incredibly broad definition of IRC.