This event is hosted in Trackmania and in the title(s) TrackMania United Forever. You can participate on your own and registration is not required.
The Trackmania Builders Cup is a speedmapping event where players build a map in 30 minutes, then take 10 minutes to finish off their map by validating it. The maps are then uploaded to TMX, and the IDs are gathered and added to a server where map discovery happens in Rounds mode. Results from Rounds are Posted on Discord.
Environment mixing is allowed, as long as people can still play the map without having to install TMUnlimiter. I.E.: no moving blocks, no putting blocks or backgrounds from multiple environments into one.
The entire event takes place via the United Communities Discord server. See this link to join: https://discord.gg/BdP2NmBtb3
This event has no upcoming dates.