Several types of extensions can be in a XOE package. The XOE core contains several "Installer Services". These services are responsible for installation of a XOE package. The core installers include:
Class Installer - Installs Java classes
Resource Installer - Installs resource files into the Stash.
Binding Installer - Installs XML tag-bindings, which map an XML tag name to a Java class.
Mimetype Installer - Installs mimetype mappings, which map a file suffix to a mimetype.
Native Installer - Installs native shared object files.
Service Installer - Installs XOE services
In addition to these core installers, additional Installer Services can themselves be installed from XOE packages.
As a package is installed, it will be processed by all the available Installer Services. In other words, a single package may contain any combination of classes, native libraries, tag-bindings, etc...