Forth is an unusual computer language that has probably been applied to more varied projects than any other. It is the obvious choice when the project is exceptionally demanding in terms of completion schedule, speed of execution, compactness of code, or any combination of the above.
It has also been called “...one of the best-kept secrets in the computing world.” This is no exaggeration: large corporations have purchased professional Forth development systems from vendors such as Laboratory Microsystems, Inc., Forth, Inc. or MicroProcessor Engineering, Ltd. and sworn them to secrecy.
Some speculate (unkindly) that corporate giants prefer to hide their shame at using Forth; but I believe they are actually concealing a secret weapon from their rivals. Whenever Forth has competed directly with a more conventional language like C it has won hands down, producing smaller, faster, more reliable code in far less time. I have searched for examples with the opposite outcome but have been unable to find a single instance.