There's this service called "discord". Mostly it's free, but I think that there are some upgrades you can buy.
It's kind of IRC - but everything posted stays until the end of time. Or that Discord server goes down or gets deleted. So if you want to, you can scroll up and see what people were talking about two years ago.
Like IRC there can be different rooms. It also supports voice and video (which isn't saved, but can be recorded) and a few other things.
See
https://en.wikipedia.org/wiki/Discord_(software) for more details.