zip-center accepts n ZIP codes on the command line. It converts these ZIP codes to latitude and longitude, averages them separately, finds a ZIP code whose center is nearest the lat/lon center point, and computes the distance of each input zip code from the resulting centrally-located zip code in miles (taking into account the variable width of longitudinal differences). This allows a caller of the script to do things like pick a centrally-located venue for a meeting given the ZIP codes of the prospective attendees.
zlib is designed to be a free, general-purpose, legally unencumbered, lossless data-compression library for use on virtually any computer hardware and operating system. The zlib data format is itself portable across platforms. Unlike the LZW compression method used in Unix compress(1), the compression method currently used in zlib essentially never expands the data. (LZW can double or triple the file size in extreme cases.) zlib's memory footprint is also independent of the input data and can be reduced, if necessary, at some cost in compression.
Ásli is a register machine which can be used for learning the basic concepts of register machines. It uses Sexp program files as input and features a stack, simple arithmetics, and conditional jumps. The register machine comes with a lean Swing GUI that supports editing the program, stepping through and monitoring the registers, and the stack. It aims to be a lightweight, but usable and extendable, learning environment for students and adults that want learn about register machines and register based virtual machines.