Integral Systems Engineering is a civilian computer systems and hardware integration company working in the Colonial Fleet.
Groups from this company are aboard the battlestar Pegasus during her docking at the Scorpion Fleet Shipyards to prepare the battlestar's transition to receive upgraded software and other updates.
The company's upgrade is halted when the Cylons suddenly attack the shipyards, destroying it and forcing Pegasus to flee.
A network administrator of Integral Systems Engineering, Gina Inviere, later sabotages the battlestar's main automated weapons programming during the Battle of the Communications Relay. She is later revealed to be a humanoid Cylon (TRS: "Razor").