ALTERNATE VERSIONS
While never actually shown, both Bishop and Fitzroy mentioned that Forge played an important role in the alternate X.S.E. future timeline they both originated from. According to Bishop, Forge would take on the name Genesis after an event called the Summers Rebellion and become one of the founders of the X.S.E. (Xavier’s Security Enforcers), the organization that policed the remaining mutant population in that era. Strangely enough, there were also hints that Forge would later become the founder of the X.U.E, an underground organization that felt the X.S.E. was going the wrong way. This was never confirmed, though, and seemed somewhat unlikely, as by then Forge would have been over hundred years old. Possibly it was a time-travelling version of him, or someone impersonating him.
In the Age of Apocalypse, Forge was one of Magneto’s X-Men for a while but eventually parted ways with him over a disagreement. He then led his own little rebel band of mutants, disguised as a theatre troupe. More machine than man, Forge became a father figure to Nate Grey, whom he found after the boy had escaped from Sinister’s pens. As he tried to teach him and safeguard him from Apocalypse, Nate grew more rebellious, though, edged on by Essex, who was Sinister in disguise. Fearing Forge’s influence on the boy, Sinister eventually killed Forge, thus setting events in motion that would lead to his own death and Nate confronting Apocalypse.
The Forge of the Mutant X was a traitor to the mutant cause. He manufactured anti-mutant weapons until he was kidnapped by vampires, who intended to use him as food for the newly turned Storm, who had become a vampire after being bitten by Dracula. Storm tried to hold on to her humanity and to escape with Forge but, along the way, when she was stopped by Kitty Pryde, she succumbed to her vampire nature and renamed herself Bloodstorm. Forge stayed with her and became her lover and only food source. Eventually when Bloodstorm fell under the Goblyn Queen’s sway, Forge and Kitty left and joined the Hellfire Club to help the mutant cause.
On yet another Earth, ruled by a cruel Queen Madelyne, Forge created several devices for her, among them the engine that allowed her to send her psychic essence across the multiverse in search of Nate Greys – the ultimate weapon. The Queen took him as her lover and confided to him about her true identity – she was a Jean Grey turned bad and only pretended to be Queen Madelyne. Having intimate knowledge about both the Queen and her most important weapons, he was considered a danger and, eventually, Queen Jean had her bodyguard, Scratch, murder Forge. Still, one Nate Grey used his powers to reanimate Forge’s body long enough to learn the truth from him.
In the Ultimate Universe, a criminal young genius, Forge joined Magneto’s Brotherhood. Promised an entire country to rule by Magneto, Forge created a device to supercharge Magneto’s powers, possibly enabling him to change the magnetic poles. When he learned that Magneto intended to kill all humans, Forge showed scruples but still didn’t try to stop Magneto. Though he was incarcerated along with other Brotherhood members Forge was later freed by Mystique and they framed Lorna Dane with one of his devices which caused her power to malfunction, causing her to kill several people (as part of a plan to free Magneto). He and Mystique later attacked the Triskelion, killing several S.H.I.E.L.D. agents in the process. Forge was incarcerated but escaped again only to be eventually killed in the Savage Land during the events of “Ultimatum”.
In their very first cross-time assignment, the dimension-hopping team called the Exiles travelled to a reality where most of the world’s superhumans had been incarcerated and neutralized as part 
of a world-wide Zero Tolerance program. This was possible due to the inventions of that world’s Forge, who created sensors and devices that aided in corralling and exterminating his fellow mutants and super-beings. Forge was his generation’s Dr. Mengele and lived in the lap of luxury until he was tracked down by the Exiles. They were disgusted to see what Forge had unleashed on this world and forced him to provide him with the technology and information that would help them restore balance to this broken reality. [Exiles (1st series) #1-2]
In another timeline visited by the Exiles, the Legacy Virus had become the mutant’s Black Death, killing nearly everybody with a trace of mutant genes. Among the afflicted was Doug Ramsey. Trying to save his best friend, the alien Warlock merged with him but the Legacy Virus joined with 
Warlock’s bio-circuitry and mutated. Cypher / Warlock infected others, turning them into a new species – the Vi-Locks, who quickly became the dominant lifeform on this Earth. Among the infected, Forge became their leader, due his mutant ability to understand technology. He sent the other Vi-Locks into battle against the last few remaining uninfected heroes on Earth. When the Exiles tried to invade the Vi-Locks’ headquarters to find Cypher, whom they needed to develop a possible vaccine, Forge killed Cypher and infected Blink. The heroes nevertheless won by imploring the help of the Asgardian gods, whose blood could be used to develop a cure. It is unknown whether Forge was killed, cured or still remained a Vi-Lock. [Exiles (1st series) #20-22]
When the Exiles’ vicious rival team, Weapon X decided to take charge of an entire reality, it began the reign of King Hyperion, Weapon X’s leader. Originally, the group had been charged with the bloody task of exterminating this reality’s remaining mutants. Among the survivors was that timeline’s version of Forge, who had joined Magneto’s Brotherhood. The Brotherhood had escaped extermination by fleeing to Asteroid M, where they planned a counterattack on Earth. However, Magneto’s plan involved destroying Earth entirely with a massive meteor and Forge and several others plotted a means of stopping his mad revenge scheme. Their efforts proved futile and Earth was destroyed. Hyperion abandoned his plans to rule a single reality and along with his cruel teammates attacked the remaining mutants on asteroid M to complete their original mission. Forge was thrown into the void of space by Hyperion and died there. [Exiles (1st series) #38-40]
In the alternate future shown in New X-Men (2nd series) #29 (about six years hence) Forge is married to Storm and they had two children, Orora and Naze. At some point, Eagle Plaza was attacked by Nimrod who killed Storm. Holding his children hostage, Nimrod then forced Forge to equip him with time-travel technology to alter the past. However, Forge managed to trick the robot somewhat by sending Nimrod to an alternate timeline’s past.
In the Marvel Zombies timeline, Forge was one of a handful of mutants to escape a contagion that transformed its victims into zombie-like creatures. The majority of Earth’s superhumans were not so fortunate. Forge joined a band of Acolytes and fled to Asteroid M where they continued their efforts to counter the virus’ effects. They were joined by a badly injured Black Panther and the Wasp, who had been infected with the zombie virus and lived on as a disembodied head. Forge helped restore T’Challa’s lost limbs and built a cybernetic body that contained the zombie Wasp. Many years 
later, the group returned to Earth and founded a community called New Wakanda. Forge’s daughter married the Panther’s son and the two became close friends while raising their grandson K’Shamba together. During these long years, Forge plundered the technologies remaining on Earth and used them to protect his new home. The relative peace of New Wakanda could not last and eventually the group was attacked by the zombie hordes and forced to return to Asteroid M. They eventually formed an alliance with a band of reformed zombie heroes and Forge used his technological genius to restore their broken bodies. But the younger generation was not content with this arrangement. Malcolm Cortez, the son of the Acolyte Fabian Cortez, betrayed the others and organized a coup, killing Forge in the process.
The latest roster of the reality hopping Exiles was made up of several heroes from alternate timelines who were plugged away at the time of their deaths. Hence they can never return, as that would damage the timeline. Originating from Earth-2814, this Forge was also married to his reality's Storm. In this timeline, though, the Skrulls conquered Earth. Forge managed to destroy their command city, sacrificing himself, and seemingly perished in the explosion. He has learned of what happens after his “death” and continues serving alongside a team of Exiles to fix so-called “ripples” in time all over the multiverse.
In Old Man Logan’s future, the Wastelands, Forge retreated to his people’s reservation in South Dakota as the villains rose across the country. He fortified his home as a safe haven for those who needed it and was prepared to defend his land when the time came. As the Rhino Gang attacked the reservation, Forge’s defenses obliterated the road warriors and laid out their leader. Forge had created a Colossus XL exoskeleton in order to deliver an example to any future trespassers. He demolished the Rhino and kept his home safe from those who would take his land.
In the Age of X-Man, Forge was warden of the Danger Room Prison complex. Although mostly a crimeless “utopia,” this society prosecuted non-conformers for intimacy violations and other infractions opposed to Nate Grey’s vision of reality. Forge had dreams about using his facility to encourage the rehabilitation of offenders, but in truth it only existed to remove the unwanted from sight and telepathically brainwash them back into compliance. Once Forge came to understand how little opportunity for reform was actually being offered in the Danger Room, he disabled the power negating collars to allow the prisoners a chance for freedom.