One of the very first computer drawing programs with a graphical user interface is now on display at the Computer History Museum, with the full source code available for all to see.
The 17,101 lines of code represent what was revolutionary at the time: a program that allowed users to point-and-click to create images on a screen. That was in 1984.
The MacPaint software was included in the very first Mac computer. Apple has also donated the source code for another of its early drawing programs, QuickDraw, to share its early history with everyone.
The official museum description of MacPaint reads as follows: "MacPaint is the drawing program application which interacts with the user, interprets mouse and keyboard requests, and decides what is to be drawn where. The high-level logic is written in Apple Pascal, packaged in a single file with 5,822 lines. There are an additional 3,583 lines of code in assembler language for the underlying Motorola 68000 microprocessor, which implement routines needing high performance and some interfaces to the operating system."
Apple continued to support MacPaint with updates and upgrades through 1988, and it was still available on Mac computers until 1998. Today, anyone who uses Photoshop still experiences something that roots back to the 26-year-old software application.