Weapon Minus
A countermeasure to the Weapon Plus program created by S.H.I.E.L.D.
Weapon Minus was established as a covert organisation within the Weapon Plus program during the early days of the program before it was closed off and only conducted within The World , a research station that speed of time could be manipulated to go through decades in a matter of days. Weapon Minus was funded by many of the same individuals and groups that also pushed research and development with most of the Weapon Plus experiments, as well as even providing plans and full research of these experiments to the Weapon Minus groups so that they would be able to create effective counter-measures if these projects would go haywire and needed to be eliminated quickly.
Based on the known history of Weapon Minus, it seems that it was mostly a abstract failure, as one of the key projects being worked upon as a counter to individuals created in particular with the Super Soldier Serum (such as Captain America , Nuke) had the funding and test subjects pulled completely, which led one of the main scientists from that project, Horace Littleton , into using his LSD/Super Soldier Serum hybrid on himself. Dubbing himself "Dr. Mindbubble" after he found that he could create bubbles that trapped people in seemingly inescapable dream-states. he attempted to take down S.H.I.E.L.D. but was arrested and all evidence of his research completely destroyed in the process.
As well as this, it could be argued that the T.E.S.S.-One (Total Elimination of Super-Soldiers) robot was a example of a precursor Weapon Minus program, as it was designed at first to be a mass manufactured safety measure to ensure that the Super Soldier's created by the Serum would not seek to try and take over America with their enhanced physical capabilities (which was completely valid until the creator of the Serum, Professor Erskine, was shot and killed, as he was the only person who knew how to develop the Serum perfectly, thus the threat of a Super Soldier takeover was completely invalidated). However, it was not developed by any governmental organisation, but rather, the paranoid creator of the robot, Professor Schumann.
While the current status of Weapon Minus is unknown, it seems that it has been defunct since the Weapon Plus projects moved into The World, possibly due to the failure to develop any correct countermeasures against the Weapon Plus creations, as well as the fact that Weapon XII, dubbed "The Huntsman" had already had a developed kill switch built into the DNA of the creature. This perhaps suggests that Weapon Plus simply developed the counters for their own creatures independently using The World, rather than a separate group creating it.