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# Forth
Forth is a very good [minimalist](minimalism.md) [stack](stack.md)-based untyped [programming language](programming_language.md) that uses [postfix](notation.md) (reverse Polish) notation. It is yet much simpler than [C](c.md), it's very [elegant](elegant.md) and its compiler/interpreter can be made very easily, giving it high practical freedom (i.e. not being practically controlled by any central organization); it is used e.g. in space technology and embedded systems as a way to write efficient [low level](low_level.md) programs that are, unlike those written in [assembly](assembly.md), [portable](portability.md) (there even exist computers directly running Forth in hardware). Forth was the main influence for [Comun](comun.md), the [LRS](lrs.md) language.
Forth ("fourth generation" shortened to four characters due to technical limitations) is a very good [minimalist](minimalism.md) [stack](stack.md)-based untyped [programming language](programming_language.md) that uses [postfix](notation.md) (reverse Polish) notation. Its vanilla form is yet much simpler than [C](c.md), it's very [elegant](elegant.md) and its compiler/interpreter can be made very easily, giving it high practical freedom (i.e. not being practically controlled by any central organization); it is used e.g. in space technology and [embedded](embedded.md) systems as a way to write efficient [low level](low_level.md) programs that are, unlike those written in [assembly](assembly.md), [portable](portability.md) (fun fact: there even exist computers directly running Forth in hardware). Forth was the main influence for [Comun](comun.md), the [LRS](lrs.md) programming language. In its minimalism Forth competes a bit with [Lisp](lisp.md).
{ It's kinda like usable [brainfuck](brainfuck.md). ~drummyfish }
{ It's kinda like usable [brainfuck](brainfuck.md). Also there used to be a nice Forth wiki at wiki.forthfreak.net, now it has to be accessed via archive as it's dead. ~drummyfish }
It is usually presented as [interpreted](interpreter.md) language but may as well be [compiled](compiler.md), in fact it maps pretty nicely to [assembly](assembly.md).
{ There is also some discussion about how low level Forth really is, if it really is a language or something like a "metalanguage", or an "environment" to create your own language by defining your own words. Now this is not a place to go very deep on this but kind of a sum up may be this: Forth in its base version is very low level, however it's very extensible and many extend it to some kind of much higher level language, hence the debates. ~drummyfish }
There are several Forth standards, most notably ANSI Forth from 1994 (the document is [proprietary](proprietary.md), sharing is allowed, 640 kB as txt).
It is usually presented as [interpreted](interpreter.md) language but may as well be [compiled](compiler.md), in fact it maps pretty nicely to [assembly](assembly.md). Even if interpreted, it can still be very fast. Forth systems traditionally include not just a compiler/interpreter but also an **interactive environment**, kind of [REPL](repl.md) language shell.
There are several Forth standards, most notably ANSI Forth from 1994 (the document is [proprietary](proprietary.md), sharing is allowed, 640 kB as txt). Besides others it also allows Forth to include optional [floating point](float.md) support.
A [free](free_software.md) implementation is e.g. GNU Forth ([gforth](gforth.md)) or [pforth](pforth.md) (a possibly better option by LRS standards, favors [portability](portability.md) over performance).
Forth was invented by Charles Moore in 1968, for programming radio telescopes.
## Language
Forth is case-insensitive (this may however not be the case in some implementations).