Slash'EM (Super Lotsa Added Stuff Hack -- Extended Magic) is a variant of the hugely popular roguelike game NetHack. It adds more monsters, more objects, more dungeon levels, more roles, and more races, shopkeeper services, and techniques for you to use, and invisible objects and gypsies for those who feel lucky. It also comes with a GTK windowing interface and higher resolution tile sets as options.
Racket (formerly PLT Scheme) is a programming language suitable for implementation tasks ranging from scripting to application development, including GUIs, Web services, etc. It includes the DrRacket programming environment, a virtual machine with a just-in-time compiler, tools for creating stand-alone executables, the Racket Web server, extensive libraries, documentation for both beginners and experts, and more. It supports the creation of new programming languages through a rich, expressive syntax system. Example languages include Typed Racket, ACL2, FrTime, and Lazy Racket.
GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
makeself is a small shell script that generates a self-extractable compressed TAR archive from a directory. The resulting file appears as a shell script, and can be launched as is. The archive will then uncompress itself to a temporary directory and an arbitrary command will be executed (for example, an installation script). This is pretty similar to archives generated with WinZip Self-Extractor in the Windows world.
C-Kermit is a combined serial and network communication software package offering a consistent, medium-independent, cross-platform approach to connection establishment, terminal sessions, file transfer, character-set translation, numeric and alphanumeric paging, and automation of communication tasks. Recent versions include FTP and HTTP clients as well as an SSH interface, all of which can be scripted and aware of character-sets. It supports built-in security methods, including Kerberos IV, Kerberos V, SSL/TLS, and SRP, FTP protocol features such as MLSD, and source-code parity with Kermit 95 2.1 for Windows and OS/2.
Calc is arbitrary precision arithmetic system that uses a C-like language. It's useful as a calculator, an algorithm prototype, and as a mathematical research tool. More importantly, calc provides a machine-independent means of computation. Calc comes with a rich set of builtin mathematical and programmatic functions.