Adobe Photoshop
February 1990 (version 1.0)
A program for editing pictures on a computer, written by the brothers Thomas and John Knoll. It became so common that “photoshop” became a verb.
How it began
In 1987 Thomas Knoll, a PhD student, wrote a program to show greyscale images on his Mac. His brother John, at Industrial Light & Magic, saw what it could do. Adobe licensed it and released Photoshop 1.0 in 1990.
How it works
A picture is a grid of pixels, and Photoshop changes their values: brightness and contrast with curves, colours, retouching and cloning, and from 1994 layers that can be stacked and masked.
Why it mattered
It moved the darkroom onto the computer. Magazine production, advertising and then photographers adopted it. It also made changing pictures easy, raising questions about trust in photographs.
Limits and what replaced it
Lightroom and other tools now handle everyday edits of raw files. AI editing and generative tools carry its questions much further.
Today
Still the industry standard, now with AI tools; editing is part of almost every photo.