AdaYaml is an experimental YAML implementation in Ada 2012. Experimental means that it does not conform to any released YAML specification. Instead, it is a testbed for the proposed YAML 1.3 standard. This list of RFCs gives an overview of the differences between YAML 1.2 and upcoming YAML 1.3. Since YAML 1.3 is not finished, everything is due to change.

However, most of the changes for YAML 1.3 are cosmetic and have been carefully edited to not break common YAML 1.2 documents. So if you are searching for a YAML 1.2 implementation, AdaYaml may still be a viable option for you which only breaks in rather obscure edge cases.

Currently, AdaYaml implements parsing and presenting YAML data, i.e. you can use it to transform a character stream (a file, a string, …) into a sequence of YAML events and vice versa. There also is currently a DOM API which allows you to transform a YAML input to a DOM structure and vice versa. AdaYaml currently does not support serialising arbitrary Ada data structures.


The parser is pretty well-tested with the external yaml-test-suite which strives to be part of the upcoming YAML 1.3 standard. Other parts of the API have been tested less extensively.

Project Goals

The goals of this project are:

AdaYaml is not designed to be used under hard memory constraints.


Releases are available as tags of the GitHub repository.


AdaYaml is available under the terms of the MIT license.