These documents provide developers, which might be implementing a new module or plugin.
To avoid wrestling with missing includes and concatenating include-paths, ESRender provides an autoloading-feature by registering the static method Phools_Autoload::autoload() as class-loader, using PHP's __autoload()) mechanism. This requires a certain class-naming and on-disk-file-structuring. To learn more about this, please see PEAR's or Zend framework's naming conventions.