To understand the material below, you should first be familiar with Oni's data files on a general level, so OBD is recommended reading. To learn how to make your own mod in the package format used by the AE Installer, see Making a mod package. Following is a technical description of how mods are installed, from start to finish.
The Anniversary Edition Seven introduced a revised framework which installs into the directory Oni/AE/, separate from any previous Editions, which installed into Oni/Edition/.