The Grammatical Framework is a grammar formalism based on type theory. It consists of:

• a special-purpose programming language
• a compiler of the language
• a generic grammar processor

The compiler reads GF grammars from user-provided files, and the generic grammar processor performs various tasks with the grammars:

• generation
• parsing
• translation
• type checking
• computation
• paraphrasing
• random generation
• syntax editing

GF particularly addresses four aspects of grammars:

• multilinguality (parallel grammars for different languages)
• semantics (semantic conditions of well-formedness, semantic properties of expressions)
• grammar engineering (modularity, abstractions, libraries)
• embeddability in programs written in other languages (C, C++, Haskell, Java, JavaScript)

The simplest way of installing GF is with the command:

cabal install

For more details, see the download page and developers manual.

On 2018-07-25, the monolithic GF repository was split in two:

1. gf-core — the GF compiler, shell and runtimes
2. gf-rgl — the resource grammar library

The former repository is now archived and no longer updated. The split was performed using this script and the output of that script is here.