Screenlets are small owner-drawn applications (written in Python) that can be described as “the virtual representation of things lying/standing around on your desk”. Sticknotes, clocks, rulers, youtube, gmail and more. Screenlets are free opensource software released under GPL License. Screenlets use GTK2 & Cairo for drawing and windowing. The goal of the Screenlets base-classes is to simplify the creation of fully themeable mini-apps that each solve basic desktop-work-related needs and generally improve the usability and eye-candy of the modern composited Linux-desktop.
screenlets are easy to use and there are hundreds of free screenlets avaialble for download.