Gatete Mario Engine
From Mario Fan Games Galaxy Wiki
Gatete Mario Engine is a series of open-source engines developed by Gatete since February 2008.
D.Y.O.S.M.E
Dark Yoshi Open Source Mario Engine or D.Y.O.S.M.E for short is Gatete's very first engine. This was developed with Game Maker 7
The engine made use only of DnD (Drag and Drop) and it was poorly commented.
The engine can be downloaded here: [1]