ETV is a personal video recorder (PVR) especially suited for European use. It can schedule by hand or according to rules based on XMLTV. It can also time-shift. The recorder runs on Linux, and the scheduler and frontend on either Linux or Windows. Its GUI is designed to be used with a remote on a TV screen.
Apple's QuickTime multimedia architecture has some features that can be exploited through server-side scripting and HTML embedding, but it's something of a black art. There is confusion and inconsistency in how best to embed QuickTime in Web pages, deal with QTVR, let movies talk to each other, pass XML QTLists back and forth between movies and servers, and much more. PEAR::QuickTime hopes to expose this in a clean and elegant way so that QuickTime can reach the audience it deserves. It aims to provide a simple and consistent interface to these features through a set of PEAR-compatible PHP classes and functions.
PyMei is a Python media center application. It's designed to run as a full screen application on an HTPC, navigated by a keyboard or an LIRC input device. It plays videos or shows other types of media using external programs like mplayer. With its plugin support and themeability, it's aiming to be a very extensible and customizable media interface.