Macintosh Programmer's Workshop (MPW) was a software development environment for the Classic Mac OS, written by Apple Computer. For Macintosh developers, it was one of the primary tools for building applications for System 7.x and Mac OS 8.x and 9.x. Initially, MPW was sold as a commercial product but Apple eventually made it a free download. On Mac OS X, it was replaced by the Project Builder IDE that was eventually transformed into Xcode.
It was designed specifically for professional Macintosh software developers. It brought together a comprehensive collection of development tools designed to support C, C++, and assembly-language programmers who are writing software for Mac OS 7.x/8.x/9.x. MPW was an open, configurable, and scriptable development environment which provides the flexibility to support complex software development projects for 68K and Power Macintosh systems.