How It Works Features Apps Downloads Plex Frequently Asked Questions FAQ - Plex Media Player A big part of Plex Media Player is released under a Open Source license (GPLv2) and we are actively encouraging users to contribute and help us improve the host part of the application. Plex Media Player is composed of two main components or layers. The "host" layer is the layer that interacts with your OS, plays video and music, and also loads the interface via a Chromium process. The "client" layer is our HTML5-based web-client, that's responsible for communication with plex.tv as well as your media server and renders the UI you see on screen. We are making the host layer of this application open source. The web-client layer will be downloaded from our servers during the build phase as a binary. With the host being open, you can help with the f...