 Mesa was compiled into a stack-machine language, purportedly with the highest code density ever achieved (roughly 4 bytes per high-level language statement).This was touted in a 1981 paper where implementors from the Xerox Systems Development Department (then, the development arm of PARC), tuned up the instruction set and published a paper on the resultant code density.Mesa was taught via the Mesa Programming Course that took people through the wide range of technology Xerox had available at the time and ended with the programmer writing a "hack", a workable program designed to be useful.