Link Hypertext Application Language

HAL is a simple way of linking with JSON or XML.

It provides a set of conventions for expressing hyperlinks to, and embeddedness of, related resources - the rest of a HAL document is just plain old JSON or XML.

HAL is a bit like HTML for machines, in that it is designed to drive many different types of application. The difference is that HTML is intended for presenting a graphical hypertext interface to a ‘human actor’, whereas HAL is intended for presenting a machine hypertext interface to ‘automated actors’.