The Illinois Institute of Technology Research Institute. Founded in 1936 by IIT as a non-profit research institute. They have laboratories all over the United States; their headquarters is on the IIT campus on the South Side of Chicago. Their largest customer is the Department of Defense; as such, most of their research is classified.
They had a moment in the news when they were picked to analyze Carnivore. Oddly enough, their findings amounted to "It's just fine."
I worked for IITRI for a while, in the Joint Spectrum Center in Annapolis.