KeenRush was an administrator of the Public Commander Keen Forum but resigned because of not having the time and energy.
Author of the first Keen mod ever, Yorphius II. My other released mods are Episode Smile, which is quite notorious, and A New Dope, much easier than ES, but what I've heard, still difficult. And more recently, Fall Up, which is more experimental and puzzle-oriented than my previous mods. The latest is Commander Keen: Extinction, which is again rather experimental and puzzle-oriented (but features all-new enemies, their code written from scratch). Tip: I've heard using a DosBox with savestates will help a lot in playing these mods!
Also the owner of keeniverse.net. It's doubtful the site will ever have any meaningful content again.