If you install XHGui as a dependency of another project with Composer it is always directly in the "vendor" folder of the project (e.g. "projectname/vendor/Xhgui 2"). In "projectname/vendor" there is always the "autoload.php" of the Composer being used by the project. If you would install XHGui with the provided install.php you would have a folder structure such as "projectname/vendor/Xhgui 2/vendor/autoload.php". So then you would have two autoload.php in your project...The intention of Composer is to have a flat vendor hierarchy with only one "vendor" folder.