feh is a fast, lightweight image viewer that uses imlib2. It is command line-driven and supports multiple images through slideshows, thumbnail browsing or multiple windows, and montages or index prints using TrueType fonts to display file information. Advanced features include fast dynamic zooming, progressive loading, loading via HTTP (with reload support for watching webcams), recursive file opening (slideshow of a directory hierarchy), and mouse wheel and keyboard control.
GuitarTeX is based on the idea of Chord. It takes a Chord file containing Chordpro directives to produce good-looking and easy-to-play song sheets for guitarists in PostScript or PDF format. You can use all available LaTeX features and packages to create a songbook or a single song sheet as you like it. If you don't know very much about LaTeX you can create pstscript or PDF output automatically. There also is a Web-based version on the GuitarTeX homepage that produces HTML output, which may be used without installing anything on your local computer.
KLeds is a tool intended for keyboards without LEDs (lights). After starting it docks to the KDE Panel and shows the current state of the keyboard lights. It is useful for keyboards like the Logitech Cordless Desktop or similar which have no NumLock, CapsLock, or ScrollLock lights. It only works if X is using the XKB keyboard extension. It is aware of the special keys some keyboards have, so that any command can be mapped to one of those keys.
SendIP is a command-line tool to send arbitrary IP packets. It has a large number of options to specify the content of every header of a RIP, RIPng, BGP, TCP, UDP, ICMP, or raw IPv4/IPv6 packet. It also allows any data to be added to the packet. Checksums can be calculated automatically, but if you wish to send out wrong checksums, that is supported too.
DINO is a realtime visualization program for structural biology data, including protein and nucleic-acid coordinates, molecular surfaces, electrostatic potentials, electron densities, surface topographs (from AFM), and MD trajectories. It supports PNG, PostScript and POVray (3.1g and megapov) output. Supported platforms are Linux/i386, Linux/PPC, IRIX, Sun, OSF1, and MacOS X.