Jens Segers, developer at Teamleader and author of the popular Optimus and laravel-mongodb packages, wrote about an alternative to controllers.

Let me introduce you to request handlers. The concept is very simple, yet very unknown to a lot of PHP developers. A request handler is basically a controller, but limited to one single action. This concept is very similar to the Action-Domain-Responder pattern which was proposed by Paul M. Jones, an alternative for the MVC pattern that focuses on a more clear request to response flow for web applications.