The API module implements a subset of the Doxygen documentation generator specification, with some Drupal-specific additions. Standards for how to write Drupal documentation that this module can parse (and that conforms to Drupal coding standards) are on http://drupal.org/node/1354.
Note that whatever version of the API module you are running, you can set up an API site to display code/documentation from any Drupal version, so in some sense, the version of Drupal you are running your API site on doesn't matter too much.
The Drupal 7 version of the API module supports parsing and displaying Drupal 4 through Drupal 8 code, so we are not planning to port this module to Drupal 8 until Drupal 7 is closer to end-of-life. See issuefor more discussion.
It is recommended to use the latest stable 7.x-1.x release of the API module.
Note: If you upgrade to 7.x-1.7 or a later release, definitely read the release notes for version 7.x-1.7 for important notes on Grammar Parser and PHP versions.
Note 2: If you decide to use a -dev version of the 7.x-1.x module, read the release notes as there may be other patches that you need to install.
No longer supported.
We welcome your contributions via the issue queue (see sidebar). The issues in the issue queue are regularly updated so that our highest-priority bugs and feature requests are marked "major" or "critical", and the ones we aren't too interested in are marked "postponed", so please choose issues accordingly to have the biggest impact and best chance of success. The project README.txt file has some information about the architecture of the module, for developers new to the project.