lee1 writes: "Where by 'Photoshop' I mean version 1.0.1, released for the Macintosh in 1990, and where by 'open source' I mean downloadable without charge if you execute the "Computer History Museum Software License Agreement". This would seem to make it open source, free as in beer, but not quite free as in speech — but I'm no expert. About 75% of the code is in Pascal, 15% is in 68000 assembler language, and the rest is data. The article features interesting screenshots of Photoshop running on an ancient black and white Macintosh — where by 'black and white' I do not mean greyscale. Much of the interface has not changed. There is also a code assessment by the 'Chief Scientist for Software Engineering at IBM Research Almaden' who admires the almost entirely uncommented code greatly, saying 'This is the kind of code I aspire to write.'"