SmallStack is the smallest and simplest way to start a website with php, oldskool style. It contains a Router and the Blade template engine. Just download the template, upload it to your webserver and you're done. Modular and with 0 dependencies.
A module is a subfolder of /modules and contains a controller (uppercase filename, contains the routes for this controller) and some Blade templates. Take a look at /modules/Default.php for the default controller. To load a module, simply include it in /public/index.php