Custom Modules in Mercury
The preceding sections have given you all of the tools that you need to make custom modules in Mercury. You have read how to create files of your own that can override controller files, module functions and module display files. So far you have learned how to use them to modify the behavior of the core Mercury. You've also read the order that Mercury tries to find which file to process and you may have noticed that Mercury always looks for a file in the per-site Mercury folder before it looks in the core files.
Since this is the case, if Mercury finds what it's looking for in your site files then it will never actually get around to looking in the core files at all!
This means that if you make your own module folder in your per-site Mercury folder then you can summon these controllers, functions and display files even though their counterparts don't even exist. This is a custom module.
You will use exactly the same techniques that you'd use to make overrides but you will be building new functionality rather than simply modifying existing functionality.
Once More For Good Measure
If you create a new folder in your html/mercury folder and put controller files, display files and functions files using the same techniques described earlier for creating then you can create your own custom modules.