[michaelt]

  I don't know why I need to use slack [...] just
  reinventing irc

Features Slack has that IRC doesn't include:

* User authentication

* Support for multiple concurrent logins by one user

* Persistent, searchable history

* (Ad-free) file and image sharing built in

* Simple integrations, like webhooks, built in.

In other words, Slack is like IRC+NickServ+Irssi+Screen+Imgur, except easier to use, in the sense that you don't need to know key combos like Ctrl+A+D or Ctrl+Alt+2, you don't have to figure out how to send such combos from your phone's terminal emulator, and you don't need access to an always-on server to run your screen session.

Of course, it's not all good; Slack has a bunch of opinionated design choices, like a channel it's impossible to leave, no ability to block users, no off-the-record option, and suchlike.

[iforgotpassword]

You are trying to try people what they should prefer. This is about openness and choice. If I've been using screen and irssi/xchat/etc for decades I don't want to learn anything new. I don't want a huge app shoved down my throat that's not nearly as customizable and integratable into my workflow as all those tools I already know. The slack app is just a horrible tool designed to get into your way and interrupt your work. Thank god we didn't jump that shittrain on my current job.

[linedash]

Not to mention the webhooks. It's trivial to implement pushing data into slack.

They even give you a hello world sample curl when you opt to add the webhook. At the simplest you can just replace the hello world text and bam -- you're sending to slack. Just takes a very simple json input.