Glossary of Terms


A source file or collection of files designed to be imported into any program.


A source file or collection of files that is part of a larger framework that may or may not be optional but depends in a large part on other modules within the framework.


Forth's analog to functions.


A package that brings together several libraries and modules for a specific purpose and is designed to lay on top of a framework as an addition to it (i.e. extend it), as opposed to abstracting it.

Stack Effect or Stack Diagram

The list of arguments and return values of a word. Here's a brief explanation of conventions used:

( arg1 arg2 -- return1 return2 )

( xt -- ) ( adr -- ) Second stack diagram describes the effect of the XT (or code), or, in the case of defining words, describes what defined words do when called.

( f: n -- f: n ) Floats

( ... n -- n ... ) Unknown list of arguments which should be preserved by a callback

( -- <name> ) Reads ahead in the input stream

( -- <code> ) The code after the word is a parameter. (Similar to does>)

( n -- x|y ) Value may be one of two things.

( n -- x y | a b ) Similar but with multiple returns.