This event is hosted in Trackmania and in the title(s) Trackmania² MultiEnvi. You can participate on your own and registration is not required. And there is a map pool that you can contribute to.
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.
The entire event takes place via the United Communities Discord server.
This event has no upcoming dates.