Photoshop got its start in 1987 when Thomas Knoll wrote software that could display grayscale images--those with a range of gray tones--on monitors that could show only black or white pixels. He and his brother, John Knoll, licensed the software to Barneyscan in 1988, then to Adobe in 1989. Adobe Photoshop 1.0 arrived in 1990, and in 1995, Adobe acquired Photoshop outright from the Knoll brothers.
Thomas Knoll (left) still works at Adobe. John Knoll (right) is a visual effects supervisor at Industrial Light and Magic, where he worked on effects in several Star Wars movies, three Pirates of the Caribbean movies, and Avatar.
Adobe Photoshop 1.0 arrived in 1990, including tools such as levels and curves for adjusting tonality and the clone tool for copying one part of an image to another.
In 1991, Photoshop 2.0 debuted paths and the pen tool, mechanisms for isolating images that proved useful in publishing. In a move that would be nearly unthinkable today, the box art for Photoshop 2.0 didn't change.
In 1993, the same year Microsoft Windows 3.1 arrived, Photoshop came to Windows with version 2.5. Adobe also released Photoshop 2.5 for two versions of Unix, Sun Microsystems' Solaris, and SGI's Irix, but later discontinued them.
Photoshop 3.0 in 1994 marked the arrival of layers, which let separate elements of an image be stacked for other, more sophisticated elements.
Slimmer models in ads is one thing, but image manipulation also let a photographer exaggerate smoke from a bombing in Lebanon. That was unacceptable to Reuters, which yanked the photo and said it wouldn't accept any others from the photographer. The copying is most evident in the smoke to the upper right.
Image manipulation existed long before Photoshop, of course, but software makes the process that much easier. This photo is from Hany Farid's collection of images showing photo-tampering throughout history.
The most dramatic departure in the Photoshop product is Lightroom. This software is dedicated to handling raw images, with all their advantages and drawbacks, though it will accommodate other formats as well.
Thomas Knoll, the original Photoshop programmer, also was an engineer on the Lightroom project, code-named Shadowland. Mark Hamburg initiated it.
Adobe used a much more open beta testing and feedback process for Lightroom than it had with Photoshop. It was beat to the market by Apple's conceptually similar Aperture, though.
Photoshop CS4 was code-named Stonehenge, and this splash screen shows through an Easter egg in the software.
Among other Photoshop code names: version 2.5 for Mac was Merlin and for Windows was Brimstone; version 3.0 was Tiger Mountain; version 4.0 was Big Electric Cat; version 5.0 was Strange Cargo; version 6.0 was Venus in Furs; version 7.0 was Liquid Sky; Photoshop CS was Dark Matter; CS2 was Space Monkey; and CS3 was Red Pill.