HAL is a simple way of linking with JSON.
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 . DHAL is a superset of hal adding support for data-templates.
This repo contains a formalised specification of DHAL (see dhal_specification.mkd).
For a friendlier, more pracitcal introduction to HAL you can read this article: JSON Linking with HAL.
If you have any questions or feedback about HAL, you can message the HAL-discuss mailing list.
If you think some part of the spec needs changing, just fork this repo and raise a pull request with your changes.