The source code of the original version of Adobe Photoshop has been made available by The Computer History Museum, based in California. Photoshop started off in the 1980s as a program called ‘Display’ written by Thomas Knoll, before being renamed ‘Photoshop’ in 1990 – the year that the first version of the software shipped to customers. The download, which is available for non-commercial use with the permission of Adobe, consists of around 128,000 lines of code. Click through for more details (and some nostalgia-inducing screenshots of Photoshop 1).