A menu‐style user interface has been developed at Lawrence Livermore National Laboratory (LLNL) for distributed control, data acquisition, and data processing. A graphical menu editor, which is itself the first application of the menu system, is used to construct or modify menu hierarchies. Unlike many menu systems, no code need be written to demonstrate a set of menus because there are no subroutine calls to make menus; developers need only write the code that performs the actions indicated by user menu picks. In addition to this rapid prototyping feature, the menu system is integrated with operating system asynchronous traps (in Unix, signals, and selects) so that it supports real‐time user interfaces for control in a distributed computer system. UFrsi1