When the brothers Thomas and John Knoll started developing Adobe Photoshop in 1987, I wasn't yet born. Today, in 2013, the software is one of the most popular programs in general and is considered the undisputed leader in the image editing sector. Thanks to Adobe and the Computer History Museum, the software will now be preserved for posterity in a very special form.
The source code of Photoshop 1.0.1 was recently released for non-commercial purposes - the 128,000 lines, after being translated into machine code, barely fit on a 3.5'' floppy disk (1.44 MB). Although code written in Pascal is certainly difficult to compile on today's (Mac) hardware, the code has great historical value.
Although the first version did not support layers or paths, a comparison with the current version Photoshop CS6 shows what amazing parallels can still be found. There are 25 years between the following screenshots - that makes your nostalgic heart beat faster! Note the almost identical arrangement of the tools on the left:
