Slack
Slack is an instant messaging app for teams, used by YSTV since it was set up by Sam Willcocks in 2015 as a replacement for IRC, Facebook groups and a some email.
There are many channels that will help you find a relevant conversation, #wikis, for example. You can customise emojis, loading messages and bots. Oh and by the way, we use it so much, Slack deletes old messages, ask any admin to Slack about that!