And video games haven't been the same since.
Yeah, Wolfenstein 3D (also an id Software product) is generally considered to have been the original first-person shooter. But Doom was the one that really made everybody stand up and take notice. Being thrown into the part of a Space Marine on a Martian moonbase who must fend off hordes of demons from Hell itself was wildly addictive fun. Some estimate that the original free shareware episode of Doom, "Knee Deep in the Dead", is the most installed piece of entertainment software in history. That the game was so easily modifiable (I still laugh whenever I think of the "Barney the Dinosaur" mod) is no doubt the biggest reason why Doom, a decade and a half later, is still being vigorously played. Doom became its own industry, just as at the same time it changed the video game industry forever.
I'll never forget the first time I played it. My good friend Johnny Yow came over one evening so we could carpool to an evening history class. He told me to "give this a try" and handed me a box containing the disks for the Doom shareware game. When I got back that evening I installed it, started playing... and it was like 2 in the morning before I quit for the night. The next evening I showed Dad how I had found the chainsaw and was using it to slice up the bad guys. Hee-hee-hee... I won't forget how he shook his head at seeing that, either :-)
Think I'll celebrate the occasion in style this morning by playing a few rounds of Doom on my Xbox 360.