Forth is a high-level programming language that works like reverse Polish notation (RPN) on a calculator. It differs from typical programming languages, like C and FORTRAN , because it is interactive. Using Forth, a user doesn't need to recompile a program to add new functionality; the user defines a new command and it is available right away.
Forth has one of the simplest syntaxes of any computer language. The syntax can be stated as: Forth code is a bunch of words with spaces between them. Each word is equivalent to a function or subroutine in a language like C. Functions are executed in the order they appear in the code. The following statement is an example that could appear in a Forth program: WAKE.UP EAT.BREAKFAST WORK EAT.DINNER PLAY SLEEP. The dots between WAKE and UP and the other words simply connect the two words to make one. Forth word names can have any combination of letters, numbers or punctuation.