If the idea of playing a time-travelling/steampunk/airship pirate RPG set in the retro-future post-apocalyptic world of 2150 and based on the music and lyrics of a steampunk rock band from Seattle doesn't appeal to you by the time you've gotten this far into this sentence, then you probably shouldn't bother with the rest of this review.
Airship Pirates uses the Heresy Engine from Cubicle 7's Victoriana RPG. It's a simple dice pool system - skill checks consist of rolling a number of d6s equal to the character's appropriate Attribute + Skill combination, and counting the number of successes (1s and 6s - 6s "explode," or are rerolled and checked for additional successes.) "Black dice" (d6s of any other color) can be issued as penalty dice by the gamemaster, and rolled against the character's roll, with 1s and 6s canceling out the character's successes.
The Dramatic Systems section contains a great system for adjudicating dangerous situations, or "Perils," and the use of Fate points to increase the amount of successes, and "Scripting Dice" to alter the aspects of the story.
The Time Travel section is a great read, which advises against meddling with the flow of time, then proceeds to explain how it is done (since we all know it's going to happen anyway). There are tips for allowing the characters to meet themselves, change their own history (or someone else's), and dealing with minor and major screwups in the timeline.
Airship Pirates clocks in at just over 300 pages, with extensive sections on the history and culture of the ruined future, a GM advice section, a short bestiary, an introductory adventure, character sheet, pirate airship deck plan, and two maps. The entire full-color book is lavishly illustrated - the art is evocative and beautiful. I particularly enjoy the "photographs" of airships. The PDF is extensively bookmarked and is completely searchable.
[4 of 5 Stars!]