A series of modules for players using early versions of D&D or simulacrum games such as Swords & Wizardry and Old School Reference and Index Compilation (OSRIC).
The designer's notes from the first module in this series summarize its purpose:
The Last Priest of Sebek Designer's Notes:
I feel that at present there are few adventure modules being written that are set in more exotic locales such as ancient Babylon, Egypt, India, Persia, Greece, or even the imaginary worlds of the late, great pulp writers H.P. Lovecraft, Clark Ashton Smith, and Abraham Merritt.