JADE was a particle detector at the particle accelerator PETRA at DESY, Hamburg. It was operated from 1979 to 1986. JADE's most important scientific achievement was the discovery of the gluon in three jet events. It also helped greatly in establishing quantum chromodynamics. JADE is an acronym for Japan, Deutschland, and England, the three countries from which the participating universities originated. The JADE jet chamber is now exhibited in the physics lecture hall at the University of Heidelberg. Although the last data taken with JADE are 20 years old, analysis continues with the most recent paper published in 2005.