Celestecord
The official Celeste Discord Server is named Mt. Celeste Climbing Association and often simply called Celestecord or clord. It is a Discord server and a central hub for discussing Celeste, its mods and collabs. It also doubles as a hub for Celeste speedruns, TASes, and modding. 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 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 this 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.