The name DereTore (デレトレ) is the short form of "Cinderella Trainer" (シンデレラ トレイナー), in response to the official abbreviation of CGSS, DereSute (デレステ), which is the short form of the game title (アイドルマスター シンデレラ ガールズ スターライト ステージ).
DereTore was at first targetted to Unity3D, creating a mini game that can play live music as in CGSS. That's why the language levels
in DereTore.HCA and DereTore.ACB were C# 4.0, the last C# version supported by Unity3D. Other projects serve as utilities
or tests, therefore restrictions on those projects are fewer. Now that the solution targets Windows PC, all the projects use the
latest C# version.
Its new goal is to improve the gaming experience, adding features to the original game. Now, the projects are more like a CGSS toolkit written in C#.
Early versions of DereTore apply WTFPL for most of the components. However, newer versions embrace MIT License.
CGSS is a music game, and its basic interacting element is note. The word score is used to reference the full collection of notes in a single gameplay, a single song. So it is more likely to be a term, rather than scores for composers or matches. See the music video game entry on Wikipedia. Still, I don't know why the developers from Cygames use "atapon", which is the abbreviation of a song, all over the code.
Please keep in mind that cheating is notorious, and tearing the game apart is illegal. So please, DO NOT transmit evil data, and DO keep the game in its original state.