Adobe Photoshop 1.0 source code now available ↦

The Computer History Museum is doing an amazing job trying not just to preserve the history of the computer revolution, but to keep it alive by getting permission to release source code for classic software. The latest is the crowning achievement of the Knoll brothers, Photoshop:

With the permission of Adobe Systems Inc., the Computer History Museum is pleased to make available, for non-commercial use, the source code to the 1990 version 1.0.1 of Photoshop. All the code is here with the exception of the MacApp applications library that was licensed from Apple. There are 179 files in the zipped folder, comprising about 128,000 lines of mostly uncommented but well-structured code. By line count, about 75% of the code is in Pascal, about 15% is in 68000 assembler language, and the rest is data of various sorts.

CHM had trustee Grady Booch of IBM comment on the (ironically not very commented) code, and he called it “well-structured”, “mature”, and “so easy to read, that comments might even have gotten in the way.”

As the post by Leonard J. Shustek continues:

…this is the kind of code we all can learn from. Software source code is the literature of computer scientists, and it deserves to be studied and appreciated. Enjoy a view of Photoshop from the inside.

I really like the phrase “the literature of computer scientists.” The only shame is that this release doesn’t include the code from the MacApp applications library, which Photoshop used and is owned by Apple. It would sure be nice if Apple made that code available as well.

Go to the linked site.

Read on Six Colors.