This directory hosts core plugins. They are feature, IO, lib and hid plugins. Each subdirectory is a standalone plugin that can be selected to be a (static linked) buildin, a (dynamic linked) plugin or disabled (not compiled at all). The selection is made in ./configure. HID plugins are user interfaces; IO plugins convert the current design to an alien format or imports from those formats; feature plugins create actions or otherwise add functionality to the system independent of which HID is running. Lib plugins provide common code for other plugins to use. Some of the plugins depend on ../src_3rd and all of them depend on core (../src). There are also internal plugin-plugin dependencies.