Concurrent C
1. <language> An extension of C with rendezvous-based concurrency. Versions for most Unix systems were available commercially from AT&T.
["Concurrent C", N.H. Gehani et al, Soft Prac & Exp 16(9):821-844 (1986)].
["The Concurrent C Programming Language", N. Gehani et al, Silicon Press 1989].
2. <language> An extension of C with asynchronous message passing.
["Concurrent C: A Language for Distributed Systems", Y. Tsujino et al, Soft Prac & Exp 14(11):1061-1078 (Nov 1984)].