Here are various links to content that you might find useful.
Two Swords, a dark fantasy expansion for Cairn—development is still underway.
Sean's Fantasy Ruleset for Adventure Games, my
work-in-progress game abandoned game. It was supposed to be a game with both Powered by the Apocalypse and OSR sensibilities, taking ideas and mechanics from both frameworks. I've since been rather impressed with the game Cairn.
13 Vaults, a resource and reference site I created for the 13th Age RPG.