Weapon Plus

In the '40s, John Sublime (a sentient bacteria that can possess non-mutant humans) founded the Weapon Plus programs to create living weapons. Despite claiming he was saving humanity from mutants, he was actually hunting mutants since they were immune to his powers. After Weapon X went rogue, John created his own facility (called "The World") and oversaw the program himself. Wolverine, Noh-Varr and Fantomex shut down the World.
Weapon I
This helped create Captain America. However. they failed to reproduce their success. One of their most notable attempt was experimenting on 300 African Americans. 299 were either killed in the experiment or by US soldiers for the sake of keeping it secret. Isaiah Bradley was the only one to survive.
Weapon II
They experimented on animals.
Weapon III
This program experimented on a mutant. He had "elastic multi-sensory skin". The mutant, now dubbed "Weapon III", was a US spy in the Cold War. After he tried (and failed) to steal the Orb of Necromancy, he was skinned alive (I wished I was kidding) by members of the Captain Britain Corps. He somehow survived and managed to get his muscles to work the same way his skin did.
Weapon IV
They experimented on animals... again.
Weapon V and VI
These programs tested on ethnic minorities.
Weapon VII
This program had experimented Vietnam soldiers. Thanks to Wolverine, they created Nuke, a villainous, drug-addicted superhuman with implants under his skin. The UK and S.H.I.E.L.D. had their own versions that created several minor characters.
Weapon VIII and IX
These programs tested on psychopaths and criminals. Those aren't the type of people you want to give superpowers.
Weapon X
This program gave Wolverine his metal-coated skeleton. However, they went rogue. They also are responsible for the creation of Sabertooth and Deadpool. Weapon X was absorbed into Department K, an Canadian government agency.
Weapon XI
There is nothing known about program Weapon XI.
Weapon XII
Huntsman (Weapon XII) was created via nanotech and artificial evolution. After a clash with the X-Cell, Huntsman joined the Super-Sentinels, a team trying to make mutant genocide acceptable to the public.
Weapon XIII
This program created Fantomex via nanotech. However, Fantomex rebelled.
Weapon XIV
The Stepford Cuckoos (telepathic quintuplets) were revealed to have been the focus in this program.
Weapon XV
Ultimaton (Weapon XV) was created as part of the Super-Sentinels. He was killed by Wolverine. Fantomex brought him back to guard a clone of the X-Men villain Apocalypse.
Weapon XVI
Allgod (Weapon XVI) was a "living religion" virus that turned people into slaves devoted to the religion. However, atheists were immune to it. It was stopped when the World was shut down.
Weapon Infinity
In the far future, this program that creates cyborg-zombies.
References

• http://en.wikipedia.org/wiki/Weapon_Plus
• http://marvel.wikia.com/Weapon_XVI