Heboris

Heboris is a game developed in 2001 by Kenji Hosimoto, aka Hosiken. Many, but not all, of its behaviors bear a resemblance to Tetris: The Absolute - The Grand Master 2 PLUS, the latest TGM series game at that point. The game was developed using YGS2K, a scripting language and runtime environment created by Urao Yane. YGS2K's language used a C-like syntax, with numerous embedded functions included to make game development easier and quicker.

Unofficial Expansion
Development of Heboris by Hosimoto has pretty much been in stasis since 2002. However, due to the nature of YGS2K in that it is an interpreted language and the source code cannot be made truly inaccessible, it became the target of modifications by anonymous third parties mainly in the 2ch community. The game underwent various modifications, including implementing similar features from later games such as Tetris The Grand Master 3, Tetris The Grand Master Ace and Tetris DS. The modified version is known in western communities as Heboris Unofficial Expansion, or Heboris U.E. as short. A second modified version, Heboris U.E. LITE, also exists, with a focus on lighter system requirements.

C++ Port
As the unofficial expansion development continued, it became evident that the developers were hitting the limits of YGS2K's specifications. This was one reason the LITE version was developed, but it itself was to bear the same burden as the original modification, as it was still based on the still environment. In 2006, an individual in the 2ch forums successfully ported Heboris and Heboris U.E. into a C++ and DirectX 9-based environment, by going through the code and re-implementing the YGS2K specific calls using DirectX. A version using the SDL library also followed shortly, and the SDL version was successfully ported over to Mac OS X as well. As of September 2006, development is still ongoing for all the modifications, including the YGS2K-based ones.