Discord is a chat program usable as an alternative to IRC.
Like IRC, it is structured around channels on servers, but unlike IRC a given community (like geohashing) will generally operate their own server, with channels per-topic (well, Discord the company hosts the storage and bandwidth and does the technical operation, but rarely becomes involved with moderation). Another difference is that IRC accepts any username whether or not it has been previously registered, and only after joining a server is registration of one or more nicknames possible (through NickServ). Discord, however, requires registration up front, although pseudonyms (both globally and per-server) are fine.
Another important difference is how easy it is to post files like images. IRC: gotta find a host. Discord: is the host. There's also a log dating back to the server's (recent) founding, although you can delete your own posts if you want which you can't really do with an IRC log someone was making (however see the warning about longevity of information at geohashing:general disclaimer).
There is currently a geohashing Discord server thanks to user:January First-of-May. We now have enough people that you need two hands to count them unless you have polydactyly! Even so, there's a nice level of chat.
If you wish to join, the invite code/link is: