Most of the development is for the military. It gets farmed to contractors who use all the same stuff you have access to, just typically several years out of date.
The ability to fully enumerate and simulate every part of the design gives them a huge hardon even though stuff frequently passes simulation and fails on the silicon. It's very common to see FPGAs in nuclear, military RF, and aerospace applications.
There are no separate tools for military use. And, the mil/aero versions of the chips are usually a generation or two behind because of the extra work to make them high-reliability, produce the required documentation, etc.
The ability to fully enumerate and simulate every part of the design gives them a huge hardon even though stuff frequently passes simulation and fails on the silicon. It's very common to see FPGAs in nuclear, military RF, and aerospace applications.