Programming, documentation, graphics templates, and most icon designs are by Al Staffieri Jr.
The source code for some Beta versions of GameMaker was created on a Macintosh Classic and Performa 550 using Microsoft QuickBASIC 1.0. It was later converted to Staz Software's FutureBASIC II using a Macintosh Performa 638 and Performa 6320.
Graphics templates were created using ClarisWorks 2.0 and 2.1, SuperPaint 3.0, and MacPaint 1.0.
Other programs used in the creation of GameMaker include ResEdit, TeachText, SimpleText, and Al's Tools.