These are the 10 Training maps and 15 Campaign maps of Spring 2020 during the Trackmania Alpha. These are the maps that alpha testers played when they first gained access to the game in April.
All of the maps have been re-saved by eyebo with new lightmaps, and thus the author names have changed to "eyebo", even though he was not the original builder of these maps.
You can also play these maps inside the Trackmania Exchange club in-game inside the "Spring 2020 (Alpha)" club campaign.
The T in the track names is short for Training. The S is short for Sport.