commercial off-the-shelf (COTS) software

See the following -

Why I Fought for Open Source in the Air Force

The AOC grew up out of a pick-up game of sorts between the users (Air Force personnel) and the vendors (commercial and government programs). The users simply bought what they wanted, and the vendors happily took their money and installed the systems. The result was a collection of standalone systems; each came installed with its own hardware and software, and there was very little sharing of resources between them. While the team made it work through sheer willpower, it was horribly inefficient, a maintenance nightmare, not user friendly, and agility was measured in decades. Our job was to take that mess and fix it...This was my first trial-by-fire experience that showed the true resistance within the Air Force and Department of Defense (DoD) to open source software...