Xclasses is a C layout library for the X Window System. All objects (called gadgets) are font sensitive, i.e. their size changes with the size of the used screen font and the size of the window. All this is done by Xclasses itself. The user may choose any kind of font style and size.
cvsroot is a script to help keep track of multiple sites when using CVS, and in particular the CVSROOT and CVS_RSH environment variables for those sites. It creates a $HOME/.cvsroot file, with shortcut names representing the different CVS sites. The new environment variables appropriate to the site selected will then be set, and a new shell will be spawned to keep the variables. In this way, you do not have to keep setting the environment yourself, and can rely on the script to keep track of things for you.