The Disruptor was built by Jack O'Neill using the knowledge of the Ancients. The weapon severs communication between the blocks of Replicators, and the cells of Human Form Replicators. (SG1: "New Order")
The Asgard had previously experimented with a weapon that would do much the same thing, without success. The Asgard also created a satellite version which could deploy the beam in space.
The Replicator Samantha Carter created a cipher to block this weapon, but the real Samantha Carter overcame this with Thor's help and with the help of Jacob Carter and Ba'al destroyed the Replicators with the Ancient weapon on Dakara. (SG1: "Gemini", "Reckoning")