Doc's Holmes Campaign Setting, from here, formatted as a booklet by Greyharp, here. What looks like a digest of the Holmes rules is actually Nicoló Maioli's Dungeon Master Reference Sheets for the Holmes edition, which you can also find at Greyharp's site. The cover can also be found there.
Oedipussy Rex's Sorcerer Character Has Warrior Adventure, from this thread on Dragonsfoot.org You can also find a support forum here: http://tripleoakleaf.myfreeforum.org/forum120.php
First, a fan-edit compilation of two Len Lakofka articles from the dipzine Liaisons Dangereuses, simply called Liaisons Dangereuses. Included here are a specialist class called the Pyrologist (or Fire-User) and an article on Dwarves & Hobbits & Magic. The other booklet, The Pyrologist, is a fan-edit only containing only the pyrologist class. The orginal articles can be found in issues #74 & #76 of Liaisons Dangereuses.
Sadly, neither PDF is currently available online, as the links I had saved for them are 404ed.
Jason Vey's Forbidden Lore and Doc's Warriors of Mars, both from here.
Jason Vey's The Age of Conan and The Age of Conan: Secrets of Archeron, both from here.
And finally . . .
A fan-edit of Dave Arneson's The Temple of the Frog. The PDF is, sadly, no longer available.
To be fair, I did download B1: In Search of the Unknown from dndclassics.com but only because it was free. I own two beat up paper copies.
Also, apparently, I need to proofread before posting . . .