The system: Core d20, with no real rules expansion. Just a few extra feats and items to allow for modern and futuristic weaponry and equipment, and one new class (essentially a Wizard with more skill points) satisfies the gamut of potential character roles. For specifics, see this article at SharpLight.org. House rules from the same site will also be used as applicable.
The campaign: In a not-to-distant future, some two decades following a global war in which anthroform and other multipedal weapon platforms stormed onto the worldwide battlefield scene with a vengeance, a collection of unlikely heroes is recruited from around the U. S. and the free world by means of a top secret screen program which identifies individuals with the rare ability to synchronize with the latest generation of experimental giant robots. Our heroes enter a classified R&D training program under the auspices of the U. S. Joint Operations Command. Their training will take them to various military bases and research locations around the world, as they encounter personal challenges, struggle with their rigorous training and testing regimen, and eventually encounter an enemy and a destiny no one could have foreseen unless he or she had watched lots of mecha anime as a child.
The heroes: Characters will be added or linked here as they are created.