The Fantasy Trip Third Dimension is a set of rules modifications for The Fantasy Trip / Melee / Wizard that allows you to use Heroscape sets instead of cardboard counters. The three dimensions create some issues, but these solve them. You’ll need The Fantasy Trip to play, but if you don’t have a copy, you can make do with Legends, which is free from Dark City Games.
Melee and Wizard is a set of rules modifications to allow you to use The Fantasy Trip / Melee / Wizard for mass combat.
And One For All is a set of free wargames rules from Eureka Miniatures for swashbuckling adventure in the tradition of the Three Musketeers.
Raum Krieg is set in an alternate history where Germany and the Allies battle it out in the skies with UFO Technology.
Here’s a set of rules for converting the large scale Warhammer Fantasy battles game to a skirmish version.