Discord is an increasingly popular platform for rich text and voice chat. Server members can have roles, which can grant access to different channels (or other special permissions). It's geared towards PC gamers, and provides numerous ways for them to connect and play games together, though many other communities have congregated on the platform.
Want your server listed here? Join one of these and message @Apollonaut#9012. Minimum requirement for listing is 100 members, and a willingness to share this website with your members. I will ultimately make the decision to add your server here after joining and verifying the quality of the server.
Please alert me if any of these invite links don't work. Sometimes the invite expires. I can fix that quickly.