The Howdy Glossary

Gallina is a functional programming language used for specifying programs and mathematical proofs in the Coq proof assistant. Coq combines higher-order logic with dependent types, allowing both specifications and code to be written in the same environment. Gallina supports various programming constructs, including pattern matching, recursive functions, inductive data types, modules for organizing larger developments.
It allows users to write formal definitions and statements about these definitions that can be formally verified using the Coq system's type checker.