Brotherhood of Mutants
In the Ultimate Marvel continuity, Forge has been dramatically re-imagined. It’s somewhat implied that it is because of humans that he lost his leg (replaced with a mechanical one) and this fact made him desirous to get his personal revenge against humankind. For that reason, he became a member of the Brotherhood of Mutants and he was asked by Magneto to invent a machine, similar to Xavier's Cerebro, that could enhance Magneto’s abilities to the extreme point where he could be able to kill every human on earth. Forge, slightly naive, agreed to build it after the promise of obtaining the whole Canada for himself.  Only at the final stages of his machine construction, he realized what he was truly doing, that is be accomplice in the killing of millions of people. He then attempted to confront Magneto, telling him that he was under the impression that Magneto would want only to terrorize the humans; but when Magneto replied that in the start of a new nation, one must make sacrifices and coldly asks him if he is hesitating, Forge (naïve but not an idiot) assures him not, but returns to his work depressed and angry.  It is implied by Tony Stark that Forge will be on trial for crimes against humanity for his role in the Magneto’s attack. 
Later it is revealed that he was freed from prison by Mystique in order to help her in realizing an intricate plan to make Magneto escape from the Triskelion.  The plan contemplated making Lorna Dane lose the control of her powers with an electromagnetic field generator built by Forge, in order to make her arrested and imprisoned in the same cell of Magneto (the only one that could contain people with magnetic power). This fact forced Havok and other members of the Academy of Tomorrow to intervene in order to free Lorna, creating in fact a diversion for the Magneto escape. Although the plan was successful, both Forge and Mystique were taken into custody. 
Wolverine vs. Hulk
During his permanence in the Triskelion, Forge is used by SHIELD staff to create any sort of thing, such as a servo-arm used by Tony Stark to play ping pong with Captain America and SHIELD's new security system.  When Wolverine is captured by S.H.I.E.L.D. and imprisoned in order to make him tell any information he possess about the Hulk, Forge decides that it is time to escape with a specially designed tuning fork and, with Wolverine's help, he succeeded. After the escape, Logan asked for one more favor from the mutant genius. They end up in one of Forge's hidden labs, where Logan requested an unbreakable collar, a device strong enough to resist any form of inertia, designed to contain Hulk's strength and to make him unable to use it. 
Powers and Abilities
Superhuman Intelligence and Intuition: Forge was a mutant with a mutation which granted him intuitive inventive genius. He has the ability to literally build whatever he could imagine and create machines that were ostensibly impossible to build.