* '''Built-in:''' Applications and functionality that come built-in in the HDA base system. They cannot really work outside.
* '''Web Apps''': these are [https://github.com/amahi/platform/blob/master/doc/plugins.md applications] from the Amahi app gallery - see [[Developers/AddingApps]] for details on how to add your apps* '''HDA plug-ins:''' These are [https://github.com/amahi/platform/blob/master/doc/plugins.md applications ] that are specific to the HDA. They are mostly implemented on [http://rubyonrails.com Ruby on Rails], though they can be implemented in PHP, Python, Flash, or any other language, like C, C++, etc. We have a few of these applications at the moment.
* '''HDAized applications:''' these are applications that, with little modification, have been adapted to run on the HDA seamlessly or nearly seamlessly. We have DLNA (which is an HDAized version of [http://sourceforge.net/projects/minidlna/ MiniDLNA]).
* '''General Linux apps:''' because we're based on mainstream distributions, you can install most any Linux apps!