The third and final volume in Robinson's series about the colonisation of Mars. I see that I didn't write reviews for the first two, so to summarise: this is an incredibly detailed hard SF series covering everything that you could possibly want to know about how to turn another planet into somewhere humans could live -- and why you might or might not want to.
A couple of plot devices are used: significant natural and political disasters on Earth provide impetus for the colonisation efforts, and lifespan-lengthening technology allows our cast of characters to be around for a couple of hundred years of future history. The storytelling is generally believable and the plot sufficiently well-thought-out to keep the reader (or, at least, me) interested. I've heard criticism of Robinson's characters for being excessively shallow, but I don't think that's the case here; the technology and politics are the story, not the people, and they're fleshed out in sufficient detail that we get to see all sides of the arguments involved.
I'd thoroughly recommend the entire series -- very well-written.