Sisal
Sisal (Streams and Iterations in Single Assigment Language) is an interesting parallel functional language.
Most of the parallelism in Sisal programs comes from parallel loops.
Sisal syntax is very like conventional imperative languages, but the meaning of most statements is different in important ways.
Sisal is a single-assignment language, so that only a single value can be assigned to each named variable in each scope :
instructions ? functional expressions