From LOTOS to LNT

International audienceWe revisit the early publications of Ed Brinksma devoted, on the one hand, to the definition of the formal description technique LOTOS (ISO International Standard 8807:1989) for specifying communication protocols and distributed systems, and, on the other hand, to two proposals (Extended LOTOS and Modular LOTOS) for making LOTOS a simpler and more expressive language. We examine how this scientific agenda has been dealt with during the last decades. We review the successive enhancements of LOTOS that led to the definition of three languages: E-LOTOS (ISO International Standard 15437:2001), then LOTOS NT, and finally LNT. We present the software implementations (compilers and translators) developed for these new languages and report about their use in various application domains