Electronic Defense Laboratories, located in Mountain View, California, known in the 1960s and 1970s simply as "EDL", was a semi-private corporate entity essentially funded by the Department of Defense, but drew heavily on civilian scientific expertise from firms such as Sylvania Electronics.
It was instrumental in development of post-Distant Early Warning line defense technologies, particularly in the area of microwave devices, and pioneered strategic communications capabilities such as the ECHO Balloon project, the forerunner of modern satellite telecommunications systems.
Other projects included development of reconnaissance and countermeasures receivers for various covert and military applications.
Much of its defense work was highly classified and remained strictly 'off-limits' to the public sector.
The original article can be found at Electronic Defense Laboratories and the edit history here.