National Institute of Advanced Industrial Science and Technology
MULE was written by the researchers Satoru Tomura, Ken'ichi Handa, Mikiko Nishikimi, and Naoto Takahashi, of the National Institute of Advanced Industrial Science and Technology (AIST), which is a part of Ministry of Economy, Trade and Industry (METI), of the government of Japan. This made it impossible for the developers to assign copyright to FSF, as is usually done for contributions to GNU packages.