Early contributors included Rick Meyers (project lead and MPW Shell command interpreter), Jeff Parrish (MPW Shell editor), Dan Smith (MPW Shell commands), Ira Ruben (assembler and many of the tools including Backup, PasMat, and more), Fred Forsman (Make, Print, SADE, and assembler macro processor), Al Hoffman (Pascal compiler) Roger Lawrence (Pascal and C compilers, including the error messages), Ken Friedenbach (linker), Johan Strandberg (Rez, DeRez, RezDet), Steve Hartwell (C libraries), and Dan Allen (MacsBug, editor).