The source code for Photoshop 1.0.1, all 128,000 lines of it, is out today via the Computer History Museum, in cooperation with Adobe itself. You can download all that lovely code here if you are into such things. How could you not. The free version of Photoshop that you can snag came out in 1990.

The first version of Photoshop was all but constructed by a single person: its co-founder Thomas Knoll. That first versionphotold of Photoshop was written primarily in Pascal for the Apple Macintosh, with some machine language for the underlying Motorola 68000 microprocessor where execution efficiency was important. It wasn’t the effort of a huge team. Thomas said, “For version 1, I was the only engineer, and for version 2, we had two engineers.” While Thomas worked on the base application program, John wrote many of the image-processing plug-ins.

Thomas Knoll, a PhD student in computer vision at the University of Michigan, had written a program in 1987 to display and modify digital images. His brother John, working at the movie visual effects company Industrial Light & Magic, found it useful for editing photos, but it wasn’t intended to be a product. Thomas said, “We developed it originally for our own personal use…it was a lot a fun to do.”

Gradually the program, called “Display”, became more sophisticated. In the summer of 1988 they realized that it indeed could be a credible commercial product. They renamed it “Photoshop” and began to search for a company to distribute it. About 200 copies of version 0.87 were bundled by slide scanner manufacturer Barneyscan as “Barneyscan XP”.

The fate of Photoshop was sealed when Adobe, encouraged by its art director Russell Brown, decided to buy a license to distribute an enhanced version of Photoshop. The deal was finalized in April 1989, and version 1.0 started shipping early in 1990. Over the next ten years, more than 3 million copies of Photoshop were sold.

This news is particularly interesting as Adobe has been hard at work in recent months rejiggering the Photoshop brand. The company released a slew of online applications, and has been updating Photoshop itself to better support modern displays.

It’s interesting to note that Photoshop 1 in 1990 is far more powerful than Microsoft’s Paint in 2013.

Source: The Next Web and The Computer History Museum.