Zsh is a UNIX command interpreter (shell) which of the standard shells most resembles the Korn shell (ksh). It includes enhancements of many types, notably in the command-line editor, options for customising its behaviour, filename globbing, features to make C-shell (csh) users feel more at home and extra features drawn from tcsh.
Calcurse is a text-based calendar and scheduling application. It helps keep track of events, appointments, and everyday tasks. A configurable notification system reminds the user of upcoming deadlines, and the curses based interface can be customized to suit user needs. All of the commands are documented within an online help system.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
coNCePTuaL is a domain-specific programming language for rapidly generating programs that measure the performance and/or test the correctness of networks and network protocol layers. A few lines of coNCePTuaL code can produce programs that would take significantly more effort to write in a conventional programming language.
Kannel is a WAP gateway. It attempts to provide this essential part of the WAP infrastructure freely to everyone so the market potential for WAP services, both from wireless operators and specialized service providers, will be realized as efficiently as possible. It also works as an SMS gateway for GSM networks. Almost all GSM phones can use it to send and receive SMS messages, so this is a way to serve many more clients than just those using a WAP phone. Kannel was among the first WAP gateways to be certified as WAP 1.1 compliant.
Herrie is a command line music player. It has a split-screen file manager and playlist interface and supports a number of file formats (MP3, Ogg Vorbis, wave, FLAC, etc). It also has some nice features, including a chroot() function for untrusted setups (remote logins, parties, etc). AudioScrobbler is also implemented using Curl.