Grammatical Framework: Frequently Asked Quuestions
Aarne Ranta
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===What has been done with GF?===

**Translation**: systems with any number of parallel languages, with input in one language and output in all the others.

**Natural language generation** (NLG): translation from a formal language to natural languages.

**Ontology verbalization** is a special case of NLG.

**Language training**: grammar and vocabulary training systems.

**Human-computer interaction**: natural language interfaces, spoken dialogue systems.

**Linguistics**: comparisons between languages.



===What parts does GF have?===

A **grammar compiler**, used for compiling grammars to parsing, generation, and translation code. 

A **run-time system**, used for parsing, generation and translation. The run-time system is available in several languages:
Haskell, Java, C, C++, Javascript, and Python. The point with this is that you can include GF-based parsing and generation in 
larger programs written in any of these languages.

A **resource grammar library**, containing the morphology and basic syntax of currently 26 languages.

A **web application toolkit**, containing server-side (Haskell) and client-side (Javascript) libraries.

An **integrated development environment**, the GF-Eclipse plug-in.

A **shell**, i.e. a command interpreter for testing and developing GF grammars. This is the program started by the command ``gf`` in a terminal.



===Is GF open-source?===


===Can I use GF for commercial applications?===

Yes. Those parts of GF that you will need to distribute - the run-time system and the libraries - are licensed under LGPL and BSD; it's up to you to choose which. 



===When was GF started?===


===Where does the name GF come from?===

GF = Grammatical Framework = LF + concrete syntax

LF = Logical Framework

Logical Frameworks are implementations of type theory, which have been built since the 1980's to support formalized mathematics. GF has its roots in
type theory, which is widely used in the semantics of natural language. Some of these ideas were first implemented in ALF, Another Logical Framework,
in 1992; the book //Type-Theoretical Grammar// (by A. Ranta, OUP 1994) has a chapter and an appendix on this. The first implementations did not have
a parser, and GF proper, started in 1998, was an implementation of yet another LF together with concrete syntax supporting generation and parsing.
Grammatical Framework was a natural name for this. We tried to avoid it in the beginning, because it sounded pretentious in its generality. But the
name was just too natural to be avoided. 



===Is GF backward compatible?===



===Do I need Haskell to use GF?===

No. GF is a language of its own, and you don't need to know Haskell. And if you download the GF binary, you don't need any Haskell tools. But if you want to
become a GF developer, then it's better you install GF from the latest source, and then you need the GHC Haskell compiler to compile GF. But even then, you
don't need to know Haskell yourself.


===What is a lock field?===