[1][2][3] In 1972, the B programming language, a derivative of BCPL, was brought to Waterloo by Stephen C. Johnson while on sabbatical from Bell Labs.
[7][5] In October 1976, the University of Waterloo published Laurence S. Melen's Master's Thesis, titled "A Portable Real-Time Executive, Thoth".
[14] As prior art Cheriton cited Per Brinch Hansen's RC 4000, then listed Thoth, DEMOS, and Accent together as later developments.
[15] Other influences on the development of Thoth included Multics, Data General's RTOS, Honeywell GCLS, and Unix.
[5] Later references cite Thoth as the original implementation of its particular use of synchronous message passing and multiprocess program structure, which were subsequently applied by other projects.
Inter Process Communication in Thoth is primarily accomplished by means of synchronous message passing.