Quite a few articles around to celebrate the 25th
Photoshop 1.0, but this one at The Register
seems to offer the most background detail. And some nice (or
not-so-nice) examples of its use...
And here's a video called "Celebrating 25 Years Of Doing Whatever The
Hell You Want With Photoshop":
Peter Reutemann, Dept. of Computer Science, University of Waikato, NZ
Ph. +64 (7) 858-5174