Mathomatic is a portable, general-purpose computer algebra system (CAS) that can solve, differentiate, simplify, combine, and compare algebraic equations, perform standard, complex number, modular, and polynomial arithmetic, etc. It does some calculus and is very easy to compile/install, learn, and use. The symbolic math application with a simple command-line interface is designed to be a colorful algebra calculator that is reliable, responsive, and convenient to use. The symbolic math library is lightweight and easy to include in other software, due to being written entirely in C with no additional dependencies.
OpenNetAdmin provides a database managed inventory of your IP network (IPAM). Each host can be tracked via a centralized AJAX-enabled Web interface that can help reduce tracking errors. It also has the ability to generate DHCP and DNS configuration for individual servers from the data stored in the database. There is a command line interface for batch scripting that can be accessed remotely or locally.
audiopreview is a command-line tool that plays previews of many audio file types (Ogg, MP3, etc.), video file types (AVI, MPEG, Real, etc.), and Internet streams. It can also be used as a regular command-line media file player (i.e. play the files entirely like yauap or mpc123 would).
JCmdLineProgress is a Java library to assist with progress reporting on the command line. Using simple hooks, a program can send progress messages and status information to the command line. Also, text based "spinners" can be used to provide visual confirmation that a long running but quiet program is still running. A working example is provided.
Bashinator is a bash shell script framework. It provides flexible and powerful message handling that lets you print to stdout, log (to syslog or a logfile), and mail messages with a single message function. Exhaustive information is included in messages to ease debugging. This information includes timestamps, message severity, source file, line numbers, and function names. A facility for tracing the function call stack is provided. Sub-command output can be logged by capturing the stdout/stderr of external commands to a dedicated temporary logfile. The framework also provides lockfile handling.
vmm is an easy-to-use and configurable commandline tool for administrators and postmasters, used to manage domains, alias-domains, accounts, and relocated mail users. It allows fast and easy management of mail servers. It's designed for installations using Dovecot and Postfix with a PostgreSQL backend.