I was primarily an AD&D 1st edition DM and campaign designer for over 20 years then "retired" for about 10. I'm now getting back into it because my professional illustrator/daughter and I are building a game-world/campaign and we're building it for 4th edition.
As for me, I've been doing online game design off an on for that entire period. Do a google search of "Randy Farmer" or "F. Randall Farmer" and you'll find that I'm one of the co-inventors of the avatar and the virtual world, as well as a published author on various topics.
Google pointed me to rpg.stackexchange.com as a resource (I was trying to understand Skill Challenges) - and now I'm here to stay!