Wrath of Kings is a set of demo rules for a fantasy skirmish system. It has some interesting concepts.
Rules: Fantasy
Empire Knightly Orders Army Book For Warhammer
Here’s a fan-created Warhammer Fantasy Army book for the Empire Knightly Orders. As with the others in this series, it’s very well done.
Fields of War Fantasy Rules
Fields of War is a set of free wargames rules for fantasy armies. In addition to the core rules, there also are a large number of interesting army lists.
WWI Fantasy Rules
Orks and Dwarves in a WWI setting? Sure. Here’s a set of fantasy WWI Rules.
Cult of Ulric Warhammer Army
Cult of Ulric is a new Warhammer Fantasy fan-made army sourcebook. It’s very professionally done.