Fortunately, Shadowdark's designer, Kelsey Dionne, did an interview for EnWorld and, wouldn't cha know it - she mentions how D&D influenced her game:
Old-school gaming. New-school mechanics. Danger. Speed. Simplicity.
Shadowdark RPG, currently on kickstarter and with a free
quickstart, distills fifty years of
D&D design into two pages of core rules supported by 239 monsters, 85 spells , 97 magic items, and dozens of random roll tables. Kelsey Dionne was kind enough to talk to me about her RPG.
Addendum: since the interview, Kelsey has posted
Monday Monster #2 - Crabstrosity! and
Monster Monday #1 - Brain Eaters!
Charles Dunwoody (Charlie): Thanks for talking with...