Grammatical Framework

A programming language for multilingual grammar applications


2018-07-25:The GF repository has been split in two: gf-core and gf-rgl. The original GF repository is now archived.
2017-08-11:GF 3.9 released! Release notes.
2017-06-29:GF is moving to GitHub!
2017-03-13:GF Summer School in Riga (Latvia), 14-25 August 2017 Summer School web page.
2016-09-07:Google Tech Talk on GF on Youtube.
2016-07-05:GitHub mirror temporarily not updated, due to server migration.
2016-06-22:GF 3.8 released! Release notes.
2015-06-21:Summer School in Rule-Based Machine Translation in Alacant/Alicante (Spain), 11-21 July 2016 featuring GF, Apertium, Matxin, and TectoMT. Summer School web page.
2016-06-14:New resource grammar language: Nynorsk.
2015-10-02:GF 3.7.1 released! Release notes.
2015-06-25:GF 3.7 released! Release notes.
2015-03-13:New resource grammar language: Mongolian. See library synopsis.
2015-02-09:GF Summer School in Gozo (Malta), 13-24 July 2015 Summer School web page.
2014-06-23:GF 3.6 released! Release notes.
2014-03-11: A company for commercial applications of GF has been founded: Digital Grammars.
2013-11-25: The default character encoding in GF grammar files will be changed from Latin-1 to UTF-8. See GF character encoding changes for details.
2013-10-18:New resource grammar language: Estonian. See library synopsis.
2013-09-18:New GF contributions repository, hosted on GitHub.
2013-08-06:GF 3.5 released! Release notes.
2013-07-26:Started a page with RGL Documentation and Publications.
2013-06-24:We are now running the IRC channel #gf on the Freenode network.
2013-06-19:New resource grammar language: Maltese. See library synopsis.
2013-04-25:New resource grammar language: Greek. See library synopsis.
2013-01-31:GF 3.4 released! Release notes.
2012-12-10: Resource Grammar Library coverage map, created by Tommi Nieminen.

What is GF

GF, Grammatical Framework, is a programming language for multilingual grammar applications. It is

Don't worry if you don't know most of the references above - but if you do know at least one, it may help you to get a first idea of what GF is.


GF can be used for building


GF is open-source, licensed under GPL (the program) and LGPL and BSD (the libraries). It is available for


GF was first created in 1998 at Xerox Research Centre Europe, Grenoble, in the project Multilingual Document Authoring. At Xerox, it was used for prototypes including a restaurant phrase book, a database query system, a formalization of an alarm system instructions with translations to 5 languages, and an authoring system for medical drug descriptions.

Later projects using GF and involving third parties include, in chronological order,

Here is a talk about GF at XRCE, 14 years later.

Academically, GF has been used in at least ten PhD theses and resulted in more than a hundred scientific publications (see GF publication list).

Programming in GF

GF is easy to learn by following the tutorial. You can write your first translator in 15 minutes.

GF has an interactive command interpreter, as well as a batch compiler. Grammars can be compiled to parser and translator code in many different formats. These components can then be embedded in applications written in other programming languages. The formats currently supported are:

The GF programming language is high-level and advanced, featuring

Getting help

If you need some help with GF, the first places to start are the Tutorial and Reference pages. The printed book contains all the material in the tutorial and some extra bits, and is the recommended reference for GF.

We run the IRC channel #gf on the Freenode network, where you are welcome to look for help with small questions or just start a general discussion. IRC logs (in raw format) are available here. If you have a larger question which the community may benefit from, we recommend you ask it on the mailing list.


Libraries are at the heart of modern software engineering. In natural language applications, libraries are a way to cope with thousands of details involved in syntax, lexicon, and inflection. The GF resource grammar library has support for an increasing number of languages, currently including

  1. Afrikaans
  2. Amharic (partial)
  3. Arabic (partial)
  4. Bulgarian
  5. Catalan
  6. Chinese
  7. Danish
  8. Dutch
  9. English
  10. Estonian
  11. Finnish
  12. French
  13. German
  14. Greek ancient (partial)
  15. Greek modern
  16. Hebrew (fragments)
  17. Hindi
  18. Interlingua
  19. Japanese
  20. Italian
  21. Latin (fragments)
  22. Latvian
  23. Maltese
  24. Mongolian
  25. Nepali
  26. Norwegian bokmål
  27. Norwegian nynorsk
  28. Persian
  29. Polish
  30. Punjabi
  31. Romanian
  32. Russian
  33. Sindhi
  34. Slovene (partial)
  35. Spanish
  36. Swahili (fragments)
  37. Swedish
  38. Thai
  39. Turkish (fragments)
  40. Urdu

Adding a language to the resource library takes 3 to 9 months - contributions are welcome! You can start with the resource grammarian's tutorial.