Linguist languages.yml in JSON format
Analyse languages used in a folder. Powered by GitHub Linguist, although it doesn't need to be installed.
GitHub's Linguist YAML language map provided as JSON
Get the language associated with a file extension or the extensions associated with a language using the data from GitHub's [Linguist YAML file](https://github.com/github/linguist/blob/master/lib/linguist/languages.yml)