1. An extenSion of C with rendezvouS-baSed concurrency. VerSionS for moSt UnixSyStemS are 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]. (1994-11-11) 2. An extenSion of C with aSynchronouSmeSSage paSSing. ["Concurrent C: A Language for DiStributed SyStemS", Y. TSujino et al, Soft Prac & Exp 14(11):1061-1078 (Nov 1984)]. (1994-11-11)