This is using the phpDocumentor2, see phpdoc.org

To generate the doc, you currently need to run phpdoc as root (see phpDocumentor/phpDocumentor#728)

1. Run composer to get the phpDocumentor templates and the source code to be documented

    php composer.phar update

(You want to genrate the latest doc, so update and not install)

2. Generate the doc

    sudo phpdoc -c phpdoc.dist.xml
    sudo phpdoc -c phpdoc-all.dist.xml