A very thorough book. Campaign setting, races, classes, modules, gazetteer...everything a DM needs to start a campaign in an interesting world. The time runs analogous to Earth, but the history does not. The author sets you up with a medieval campaign, but then gives options for post-renaissance, modern and futuristic play. He also gives a quick and dirty view of a playable army. The modules start at various levels for introduction into the campaign.
Caveat: This author has his tongue stuck firmly in his cheek at times with the "Assclown" class and 'snerf' guns for children.
Pros: A wonderful campaign setting, with everything needed to hit the ground running.
Cons: PDF is not bookmarked, making searching harder.