No, this is not a reference to the HAL 9000 from Clarke's 2001: A Space Odyssey,
Quick Answer
HAL is an acronym for Hypertext Application Language and is designed to provide "...a set of conventions for expressing hyperlinks in either JSON or XML." HAL is an IANA registered media type that enables RESTful APIs to return JSON (or XML) content with hypertext (aka hypermedia) that can be easily consumed by machine agents and interpreted by human agents. Because it is a registered media type, developers can specify application/hal+json as the value for the Content-Type response header.
Digging Deeper
