gEDA is a suite of electronic design automation (EDA) tools. Currently, the project offers a mature suite of free software applications for electronics design, including schematic capture, attribute management, bill of materials (BOM) generation, netlisting into over 20 netlist formats, analog and digital simulation, and printed circuit board (PCB) layout.
Nmap ("Network Mapper") is a utility for network exploration, administration, and security auditing. It uses IP packets in novel ways to determine which hosts are available online (host discovery), which TCP/UDP ports are open (port scanning), and what applications and services are listening on each port (version detection). It can also identify remote host OS and device types via TCP/IP fingerprinting. Nmap offers flexible target and port specifications, decoy/stealth scanning for firewall and IDS evasion, and highly optimized timing algorithms for fast scanning.
Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
Squeak is an OpenSource and super-portable implementation of a multi-media capable Smalltalk-80 based object-oriented programming environment. It is written entirely in Smalltalk and has a high-performance VM, created by compiling the Smalltalk VM code into efficient and portable C code. It now uses the Self language's Morphic User Interface but still provides the original MVC GUI as well.
ICI is a general purpose interpretive programming language that has dynamic typing and flexible data types with the flow control constructs and operators of C. It is designed for use in many environments, including embedded systems, as an adjunct to other programs, as a text-based interface to compiled libraries, and as a cross-platform scripting language with good string-handling capabilities.
Cdrdao records audio/data CD-Rs in disk-at-once (DAO) mode based on a textual description of the CD contents (toc-file). Features include full control over length and contents of pre-gaps (pause areas between tracks). Pre-gaps may be completely omitted, e.g. for dividing live recordings into tracks. Control over sub-channel data like catalog numbers, copy, pre-emphasis, 2-/4-channel flags, ISRC code, and index marks are provided as well. GCDMaster is a Gnome GUI front-end that lets you import MP3 and WAV files, select track markers and cut/copy/paste audio snippets before burning.