The disruptor is an important weapon in Star Trek and Trek-derived SF (like Starfleet Battles and Starfleet Command).
According to Trek canon, the disruptor is used as the main offensive battery of Klingon and Romulan warships (though in TOS, Romulan ships never actually use disruptors). No Federation ships carry disruptors, electing to use phasers instead. Some other races, such as the Lysians use disruptors also.
In Starfleet Battles, and its video game adaptations in the Starfleet Command series (except 3), disruptors are the main heavy weapons of the Klingon Empire. The Kzinti (AKA Mirak), Orion Pirates and the Lyrans also use them. Disruptors charge quickly and inflict moderate damage at medium range. This allows the Klingons, and to a lesser extent the Lyrans and Mirak, to make use of the sabre dance maneuver.
Disruptors can have two modifications: UIM and DERFACS. UIM, which stands for Ubitron Interface Modules, makes disruptor fire more accurate at short to medium range, while DERFACS (disruptor extended range fire attenuation control system) makes them more accurate at longer range. The Kzinti don't use UIM, though the Mirak from SFC do have it. (This is despite the fact that the Kzinti and Mirak are ostensibly the same race!) The same disruptor can have both UIM and DERFACS, and this is a common configuration on Lyran and Klingon warships.