...MJK,
MJK is a company located in Silicon Valley that sells timesharing on HP minicomputers. Their major business is providing access to current and historical data for the commodities market. John Walker used this system in his commodity trading days, and also used it to implement a teleconferencing system for Marinchip dealers and, later, Autodesk people. Since the system was on Tymnet, overseas participants could access it economically.