tkbiff allows arbitrary commands to be executed upon mail reception. If you like programs such as xbiff and xbiff++ but wish they were more flexible, then you'll like tkbiff. Unlike other biffs, tkbiff is fully customizable. tkbiff also doesn't waste your valuable screen space with icons; instead, it shows you the mail itself. It supports UNIX, Mac, and Windows, IMAP, POP, and UNIX-style mail files, and SSL and APOP.
Tkjmdict is a dictionary program written in Tcl/Tk which utilises the Japanese multilingual JMdict dictionary from the Electronic Dictionary Research and Development Group in Monash University, Australia. The JMdict consists of more than 150,000 Japanese entries translated to English with varying degree of support for German, French, and Russian.
tkpg is a program that provides a GUI front end to Philip Zimmermann's Pretty Good Privacy (PGP) public-key encryption system and also the GNU Privacy Guard (GnuPG/gpg) implementation. It utilizes the Clipboard Selection heavily to ease moving pgp-processed text both to and from any of your applications (such as mail reader, news reader, and editor). This removes the need to select the output text by hand or by typing in a filename, since it is usually placed in the Selection automatically for you.
tmphoto is a Web photo gallery with a fairly advanced metadata structure, allowing photos to be described in terms of place, category, persons in the photo, and events. The places, categories, persons, and events can be further described. It offers a nice browsing interface based on the metadata.
tomo3D is a multi-platform voxel-based program for the viewing and manipulation of 3D tomographic reconstructions. It offers a refined toolset to identify blurred, hardly separable 3D objects. Its tools enable global image manipulation operations as well as local manual intervention.
trash-cli is a command line interface to the FreeDesktop.org trashcan. It implements the FreeDesktop.org trash specification. For each trashed file, it will remember the name, original path, date of deletion, and permissions. It interoperates with KDE and GNOME Trash, and is CLI compatible with the rm command.