THOAN, 1994 A French roleplaying game based on the World of Tiers series. Farmer wrote an introduction to the book. Here is its official webpage.
Riverworld PC Game by Cryo Interactive. Here is a review of the game.
The 20th Anniversary Edition of Trivial Pursuit has the following question in "The Written Word" category. Not that is was ever in doubt, but here is the answer.
The novel A HOUSE-BOAT ON THE STYX was an inspiration for the Riverword series.
In the Jimi Hendrix section of the Experience Music Project (EMP) in Seattle, you will find the following display about the song Purple Haze; pic 1, pic 2, pic 3 and pic 4.
You can also go to the EMP Digital Collection. Click on Launch Digital Collection, once this loads click on "THINGS", then scroll down and click on "book", then select "Night of Light".