There is a libpurple/Pidgin plugin for Discord. As you might expect, however, it only exposes text chat and not any of the "rich" features such as voice chat or

There is a libpurple/Pidgin plugin for Discord. As you might expect, however, it only exposes text chat and not any of the "rich" features such as voice chat or emote reactions. I don't know of any free software full reimplementation of the Discord client, and I suspect such would be against their terms of service.