Lambda the Ultimate

The PROLAC language is a statically-typed object-oriented language, designed by Eddie Kohler as his Thesis at MIT and supervised by Frans Kaashoek, to produce a compiler which produces efficient compilation with minimal overheads on the resultant procotol code, based on previous experience on other protocol-specific languages like LOTOS (the functional approach used in LOTOS results in difficult protocol description and difficult to write compilers, producing poorly efficient final code), Estelle (the FSM approach is not a very good protocol model), Esterel (the same language problem as Estelle), RTAG (context-free attribute grammar approach, equivalent modeling power to extended finite state machines) and Morpheus (inflexible; inability to implement real protocols). A prolacc compiler and a almost already working implementation of TCP are offered.

Has anybody ever used one of those languages? What are your experiences with them? What other approaches can you think of to describe protocols?