xine is a free multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet. It interprets many of the most common multimedia formats available--and some of the most uncommon formats, too. All those features come in a reusable library (xine-lib) which can easily be embedded in your applications.
xlayout is a terminal-based utility to get and set information about X11 windows and the pointer. It's designed to be easily integrated into bash shell scripts and takes advantage of the X11 protocol to allow it to access remote X11 desktops. With the aid of the libease library, xlayout provides the ability to smoothly ease the windows and pointer into position.
yet another yuv viewer (yay) displays 4:2:0, 4:2:2, 4:0:0 YUV, and Y-only pictures and sequences (planar Y:U:V format). It tries to find geometry information such as _widthxheight somewhere in the path and filename (e.g. mobile_352x288.yuv or path/to/yuv/mobile_640x480x400frames/file.yuv).