Krendel is a free, universal RPG. It is really an impressive work, well written, with numerous illustrations. The mechanics are also worth a look. I can see the single roll mechanics being adapted to skirmish rules for miniatures as well as for use in RPGs.
40K Unlimited Warhammer 40K Fan Rules
40K Unlimited is a set of fan created alternative rule for Warhammer 40K.
Ninth Age Alternate Warhammer Fantasy Rules
Given the general fan anger over the direction Games Workshop has taken its Warhammer Fantasy property, it is no surprise that fan written alternatives have cropped up. One is The Ninth Age, a a set of free wargames rules for playing mass fantasy battles. It looks very well done, and has a large number of army books.
Making Streams For Your Wargames Table
Small World Productions has a short tutorial on making rivers for your wargames table.
Munera Sine Missione, Exagoni Libero Gladiator Rules
Munera Sine Missione, Exagoni Libero is a set of free wargames rules for gladiatorial combat. The author writes:
These rules are an adaption of Munera Sine Missione (v2.1) by Alan Saunders, 2002-2012, which were based on “We Who Are About To Die Demand a Recount” by Gary Comardo and published in Issue 67 of “Saga”. The special attacks were chiefly inspired by Chris Peers’s Gladiator combat rules in the Foundry Miniatures Compendium.
Main differences are :-
1. I have adapted the game for those that do not have a hex mat or prefer to play
without one.
2. “Strength” renamed “Stamina”.
3. Spear and Lasso ranges increased.
4. I have added the Arbelas, Scissor and Murmillo as fighter classes. Rules for the
Arbelai and Scissores’s special weapons have been added.
5. Modifiers on AP or Attack roll have been repeated in the weapon descriptions to
speed things up.
6. Rules for the Galerus have been added and changed slightly.
7. An Appendix of “Special Attacks” added and relevant modifiers for Appealing to the Crowd added to that table.