40-ish year old game designer who has been roleplaying for 25+ years and GM-ing for nearly 20 of those. I've been playing in my own settings and with my own ruleset for almost all of that time and WorldAnvil has finally given me a convenient option to organize it all. Previously I ran a MediaWiki with all the information, but WA is a far more slick option. I am known by many names, but the most common ones are probably Mánagarmr and Toblin.
Far too many to list, but the absolute top has to be: