What is Forth written in?

Programming language.

Programming language Year 1970 Paradigm imperative, procedural, concurrent Typing none Self-hosting yes
The Forth compiler is written in Assembly (reported). Forth is self-hosting.

Quick Facts

Designed by
Charles H. Moore
First released
1970
Typing
none
Filename extension
.fth, .fs, .4th, .fb, .f, .forth

About Forth

Forth is a programming language. Forth is executed directly by an interpreter. It supports imperative, procedural, and concurrent programming.

Forth first appeared in 1970 and was designed by Charles H. Moore. Its popularity peaked around 1985. Forth is now used mainly in specialized niches and by dedicated communities.

How Forth is implemented

In the Language Lineage dataset, Forth is self-hosting, so its own compiler is written in Forth itself. Reaching self-hosting — where a language is mature enough to compile itself — is a milestone that proves the language can handle a large, real-world program.

Forth in the language family tree

Forth drew on ideas from Lisp, APL, and Burroughs large systems and went on to influence Factor.

Sources: Wikipedia · Wikidata · Official site

Relationship Graph

All directly connected languages. Click any node to navigate to its page.

Compiler Implementation

LanguageConfidenceNotesSource
Assembly 80% Classic Forth systems were bootstrapped in assembly. Source

Languages Forth Influenced

Frequently Asked Questions

What language is Forth written in?
Forth is primarily implemented in Assembly. See the implementation section above for details and source references.
Which languages did Forth influence?
Forth influenced Factor among others.
Is Forth self-hosting?
Yes, Forth is self-hosting — its compiler can compile itself.
When was Forth first released?
Forth was first released in 1970. It was designed by Charles H. Moore.

Evidence Sources

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