Discord

 Discord  is a proprietary freeware VoIP application and digital distribution platform designed initially for the video gaming community, used by a variety of groups for chat and instant messaging, and bridged to the IndieWeb chat channels.

For the open source forum &amp; discussion platform, see:
 * Discourse

How to join
To join the community chat over Discord, please see the discuss page.

Advantages

 * The UI is easy to navigate.
 * Discord and its features are well documented (link?)

Criticisms

 * It's not self-hostable
 * Although it contributes to OpenSource the product is not OpenSource
 * Discord API and chat gateway is proprietary. This means that integration developers (i.e. people making bots) are beholden to implementing interfaces that work with Discord's specific API.
 * Content stored on discord is stuck in a silo, hidden from the rest of the web, and therefore not possible to index, search or archive.
 * Discord has no built-in data export tool, and using the API for archiving data is against the TOS