The Gauss gun is a weapon originally used by the TEC Gauss Defense Platform and, by extension, the Pirate Defense Platform. However, the TEC Rebels have outfitted their Ragnarov Titan with twelve dual turrets of Gauss guns (eight of them forward-facing and four aft-facing), creating the first ship with Gauss weaponry as standard (as opposed to Kol's Gauss Rail Gun active ability).
It is unusual among damage types in that while there are no direct damage-amplifying research for this damage type, there is both rate-of-fire increasing research topic, Quick Gauss Capacitors, (the likes of which only the Plasma damage type has, and very late in the game) and a range-increasing research topic, Highly Conductive Rails. While all but the rarest damage types (Rail Gun, Psionic Surge, Phase Cannon, Flak and Point Defense, all specific to Titans and Starbases) have damage-increasing research, the rate of fire upgrade can be considered a compensation.
Gauss Gun on Wikipedia