acoc is a regular-expression based colour formatter for programs that display output on the command-line. It works as a wrapper around the target program, executing it and capturing the stdout stream. Optionally, stderr can be redirected to stdout, so that it, too, can be manipulated. acoc then applies matching rules to patterns in the output and applies colours to those matches.
IDesk provides icons on an X11 desktop. Its features include transparency, configurable actions to run shell commands, PNG, SVG (in old versions), GIF image support, and XFT anti-aliased fonts. Other features include Imlib2 support (Imlib is deprecated), pseudo-transparency, the ability to only show captions on mouseover, tooltip on mouseover, startup notification, and more.
Net-Fu is a DHTML implementation of the classic GIMP NET-FU interface. It uses the GNU Image Manipulation Program and Xvfb to produce a wide variety of royalty-free custom and semi-custom graphics, logos, and clip art of various sorts. You simply select a style of logo from such choices as "neon", "chrome", and "crystal", specify parameters such as text string, typeface, size, and colors, and your logo is returned without further ado.