Published by Wizards of the Coast.
If the purpose of published modules is as much to provide a model for inexperienced referees as to provide a ready-made adventuring locale, then The Isle of Dread is certainly one of the most influential modules I’ve ever read. First published in 1981 as part of the Cook/Marsh Expert Set, module X1 is part of what I sometimes call the “Moldvay Pulp Fantasy Trilogy.” Not a trilogy in the literal sense, these three modules — B4, X1, and X2 — all draw clear inspiration from a number of pulp fantasy authors and stories, X1 being an homage to Burroughs, Haggard, Doyle, and Merritt (not to mention King Kong). Being a huge fan of the “Lost World” genre of pulp fantasy even then, I absolutely adored The Isle of Dread and can’t even begin to count how often I used it in my old campaign.
Read the Full Retrospective/Review at Grognardia.