Discord

Discord is a FREE (as in "beer", but more/better beer may be purchased), persistent, multi-server, multi-channel, Text and Voice service. It includes automatic link resolution for many social services such as Youtube, Spotify, InstaGram, and HTTP.

The important thing to know about Discord, as compared to other chat services, is that Discord is persistent. This allows conversations to stretch across online sessions without losing content. You can ask a question of a person that is not online at the moment, come back later and, assuming they have logged in, find your answer waiting.

After the death of the Runes of Magic IRC server, Gameforge has finally created a Discord server. It is the ONLY official Discord server.