Call of Cthulu is a role-playing game set in the context of H.P. Lovecraft’s Cthulhu Mythos. It is published by Chaosium. The game is currently on its seventh edition. I have written a great deal for previous editions of the game, especially the sixth edition.
I wrote “Blood Moon” for the Strange Aeons book.
I also wrote several 6th Edition monographs for Chaosium, which are still sold by the company on their website.
In the 1990s I wrote 48 Call of Cthulhu adventures to be distributed for free, with Chaosium’s permission. You can download the zip file containing all of them: CoC PDF