On the Tighten.co blog there's a recent post showing off some of the magic of Laravel macros and how they can make extending the basic framework functionality simpler.

Ever wanted a piece of functionality in a part of Laravel that doesn’t exist? Let me introduce you to Laravel macros. Macros allow you to add on custom functionality to internal Laravel components.

He gives an example of adding a simple "introduce" macro on the Request facade and how to put it to use. He refactors this into something more useful: returning a true/false result when checking the TLD on the current domain. He includes the code to set up the macro in the AppServiceProvider and the addition of an enhancement that adds a "where" clause to a model query when the TLD matches. He wraps up the post giving some guidance on where they should be defined and what components in the Laravel framework are "macroable".