Why not just use IRC? Is it not made for the sole purpose of having lots of users talk with each other.
* Free. You can hop onto an existing tech-focused server like Freenode, or if you want your own control, throw it on your own server(s) for pennies. If you do the latter, you have full control over all logging.
* Logging. Every client can choose what they want to log, what format the logs are in, where the logs live, etc. No more archived messages. Some IRC clients are smart enough to pull from the log to "back-fill" the messages.
* Modern Clients. Like a said above, LimeChat is a really nice IRC client. It doesn't have all the features of Slack, but do you really need all the features of slack?
* Bot Surplus. There are hundreds of bots written for IRC, in nearly every conceivable language. This was the first "integration" anyone ever used for chatting, and can integrate with anything if you put the time in. You don't get it for free, but for a community focused on programming, that's not the worst thing.
I always feel like IRC is a few protocol extensions and a few clients away from being relevant again.
/me goes back to Freenode
There are exceptions, like OFTC, but merely waltzing into the wrong place on EFnet these days is enough to get 10+ Gbit of UDP traffic directed at your IP address. I used to be fairly okay bouncing on a vhost, but now even the 12-year-olds have enough traffic to knock over a 40 Gbit port channel. An increasing number of datacenters are just filtering 6667. I'm on board with that.
Seriously, let IRC relegate itself to the dark corners of the Internet on shitty hosts and stay there, IMO.
The brute force ddos attacks I've seen are on illegal private server emulators and Minecraft et al. Maybe this is just a completely different experience by being in differnt part of internet.
That being said, their pricing is probably no better than Slack's for this purpose ($5/user/month).
Glad you like it, this year is going to be a big one for us - we're actively looking at how we can better serve large open communities, and I would suspect that will result in some nice changes to both free accounts and the pricing of paid accounts.
If anybody is interested in making IRC suck less, we've got a designer-shaped hole that needs filling... https://www.irccloud.com/jobs
I don't think it takes much to be comfortable with IRC, given the huge mix of people we have using it every day successfully. The IRC clients are really good at making users feel at home - Textual is set up for everyone in the company, although some people prefer to use Weechat.
irc is a dinosaur compared to what recent team communication software like Slack and Hipchat can do.