In the video art field there are many artworks requiring the real-time synced playback of different audio/video channels. Syncstarter sofware runs on the MIPS based HDTV WD Live players and other platforms to synchronize their parallel playback,
Frei0r video plugins
As a plugin API, Frei0r's main emphasis is on simplicity, to round up the most common video effects into simple filters, sources, and mixers that run on any hardware (software-based implementations) and can be compiled on most POSIX platforms.
Dyne:bolic GNU/Linux is a live bootable operating system equipped with a wide range of multimedia applications. Dyne:bolic is optimized to run on old computers and adopts the Linux-Libre kernel.
FreeJ is a vision mixer: an instrument for realtime video manipulation used in the fields of dance and theater performance, veejaying, medical visualization, and TV. Multiple layers can be filtered through effect chains and then mixed.
Hasciicam makes it possible to have live ASCII video on the Web. It captures video from a TV card and renders it into ASCII, formatting the output into an HTML page with a refresh tag or in a live ASCII window or in a simple text file.