This is the fourth supplement for the d20 Modern roleplaying game. Rather than a single game world, it presents rules and settings to mix and match, enabling you to create a future world to suit you.
Among the new stuff in this book are rules for spacecraft, city-stomping mechs, cybernetic enhancements, robots (including Terminator-style characters) time and dimensional travel. The amount of information can be almost overwhelming at first, but as I said, just take what you need.
There are plenty of new advanced classes and enemies as well, although some of the latter have previously appeared in the Menace Manual. All in all, a well put-together toolbox for any GM who wants to run a future campaign or use advanced equipment in their current one.