Celestecord
The official Celeste Discord Server, named Mt. Celeste Climbing Association and often simply called Celestecord, is a Discord server and a central hub for discussing Celeste (the 2018 game), alongside with a large variety of Celeste mods and collabs. It also doubles as a hub for Celeste speedruns and TASes. The link to the server can be found here.
Celestecord is notable for having a unique subculture, and a unique way of reacting to a variety of things. Frogeline, an emoji featuring a frog with Madeline's hair, is perhaps its most notable element; however, a variety of other in-jokes, emotes and terms have been coined there. Radeline is perhaps a more controversial component of the server, its appearance being glad Madeline with rad glasses placed on top. Many have made suggestions within the server to remove the capability of reacting in the designated memes channel due to most messages within that channel being reacted to with the emoticon.
Many of Celeste's developers are present on Celestecord. These include Maddy Thorson, Noel Berry, Kevin Regamey (representing Power Up Audio), Amora B., Pedro Medeiros, and Heidy Mottas.