To celebrate the 25th anniversary of the image editing software Photoshop last year, online education company Lynda.com created the short documentary "The Evolution of a Tool Palette" telling the history and the progress the program has undergone through the years.

For more, watch the free series "Celebrating Photoshop: A 25th Anniversary Retrospective" at Lynda.com (you don't need to sign up for a free trial to watch this).

For over two decades, Photoshop has been an essential part of the digital artist's toolset. To celebrate its 25th anniversary, we've taken a look back at Photoshop's history: from the rise of desktop publishing and digital photography, to the evolution of Photoshop's tool palette and its sometimes controversial but necessary role in modern photojournalism.

We interview early adopters and pioneering artists such as Bert Monroy, Chris Orwig, and Douglas Kirkland, as well as the people responsible for guiding Photoshop's development: John Nack, Russell Brown, and current product manager Bryan O'Neil Hughes. Konrad Eek and Sean Adams also explain what life was like before Photoshop and how this beguiling tool has democratized design and darkroom photography.