Many webtrees functions are provided by “modules”. Modules allows you to add additional features to webtrees and modify existing features.
A module is a folder containing a file called module.php.
There may be other files in the folder, such as CSS, JS, templates,
languages, data, etc.
To install a module, copy its folder to /modules_v4.
To uninstall it, delete its folder from /modules_v4.
Note that module names (i.e. the folder names) must not contain
spaces or the characters ., [ and ]. It must also have a
maximum length of 30 characters.
TIP: renaming a module from <module> to <module.disable>
is a quick way to hide it from webtrees. This works because
modules containing . are ignored.
To write a module, you need to understand the PHP programming language.
There are several example modules available at https://github.com/webtrees
The built-in modules can be found in app/Module/.
These contain lots of useful examples that you can copy/paste.