A new version of the more complex Simutrans fork is now available, based on Simutrans 112.3

Simutrans experimental is based on Simutrans standard, it extends several aspects of gameplay with the aim of greater economic and operational complexity. With its 112.0 release Simutrans standard incorporated a number of very thorough changes below the surface. Many of these changes involved parts that are different in simutrans experimental. Implementing the upstream changes of simutrans 112 in_experimental_ involved a lot of meticulous work.

On top of that experimental was not only patched to the state of simutrans 112.0, but rather 112.3, the latest version, including countless improvements such as: arbitrary height of map borders; new landscape (two slope inclines); support for scenarios; aspects specific to simutrans experimental only were also improved: better performance, fixed vehicle physics simulation; less cpu required for private car modeling;

cf: forum release thread