From Cakebread & Walton, the folks behind the Abney Park’s Airship Pirates and Clockwork and Chivalry RPGs, there is now a Steampunk book for the OneDice system:
Quick and easy steampunk role-playing rules
“OneDice Steampunk is a game of Victorian science fiction adventure in a world on the brink of war and revolution. Aerial steam carriages streak across the skies, steamtanks rumble along the ground, and the automatons keep the factories moving.
Whether you want to play steampunk games in a world of your own devising, or adventure in the ready-made alternate 19th century described within, all the rules you need are in this book.
There are additional “skins” for adding Gothic Horror, Lost Worlds, automaton and child Adventurers to your games. Grab a copy of OneDice Universal and you could also add magic, spaceships or superheroes!
Whether you’re a lordly Have or a poverty-stricken Have Not, all you need is a stiff upper lip and a pair of goggles and the sky’s the limit!”
There’s a number of other books in the OneDice series: traditional offerings like Fantasy, Pulp and Cyberpunk, but more esoteric offerings like WWI, Twisted Tomorrow and OneDice versions of their own classic games: Pirates & Dragons and the aforementioned Airship Pirates (if you needed even more steampunk goodness).
If you want a taste you can pick up the OneDice Quickstart rules here (for pay what you like): http://www.drivethrurpg.com/product/143309/OneDice-Quickstart