CTWM is a highly-configurable window manager based on the classic TWM window manager. It supports xpms, multiple workspaces, advanced icon managment, animated icons and backgrounds, 3D titles and borders, etc. It offers rudimentary Gnome support and is backwards-compatible with TWM.
CTSim is a Computed Tomography simulator. It simulates the process of obtaining x-ray data around a phantom object. It then uses various reconstruction algorithms for reconstructing the original image. It supports animation of projection and reconstruction processes, 3-dimensional viewing using OpenGL as well as cross platform support using GTK and Win32.
ctrlxmms is a small Perl script designed to increase the useability of XMMS. With it, you can use most of the common GUI functions of XMMS from the CLI. You also have a few handy commands which are not available from the GUI. Together with lirc and a remote (eg. Anir Multimedia Magic), this is a wonderful tool.
ctm.pl is a Perl script which generates Apache type maps for use with mod_negotiation. Useful if you have a lot of images available in different formats you need type maps for, especially if you don't want to use MultiViews to decide which of them will be sent back to the requesting browser.
ctk-nettools provides functions to deal with templates in Perl. It also provides other functions to do log, to get value from db-file (Btree or Hash), and to get the date. The principle of the templates handling is to use an HTTP server to serve the templates. There's also a cache handling to speed up templates loading and to have a copy in case of a crash of the templates server.
cthumb allows you to create Web albums of digital pictures with thumbnails, captions, and several different views of the collection, including (optionally) several languages and resolutions. An album is composed of a series of pages, each composed of a collection of pictures. You can have several annotations per picture, and can customize almost everything in the way the albums look on the screen.