Nerdtool allows you to display many things directly on top of your desktop; weather reports, headline news, and system vitals are just a few uses.
Nerdtool is capable of displaying shell outputs with ANSI escaped formatting, but can also manipulate the final output's colors, size, and font. If more intricacy is desired, Nerdtool is also capable of displaying images, HTML documents, and other higher forms of media.