Free drawing software for Windows, Mac OS X, and Linux
Dia Diagram Editor is free Open Source drawing software for Windows, Mac OS X and Linux. Dia supports more than 30 different diagram types like flowcharts, network diagrams, database models. More than a thousand readymade objects help to draw professional diagrams. Dia can read and write a number of different raster and vector image formats. Software developers and database specialists can use Dia as a CASE tool to generate code skeletons from their drawings. Dia can be scripted and extended using Python.
An award-winning drawing program for children ages 3 to 12
Tux Paint is a free, award-winning drawing program for children ages 3 to 12. It combines an easy-to-use interface, fun sound effects, and an encouraging cartoon mascot who guides children as they use the program. Kids are presented with a blank canvas and a variety of drawing tools to help them be creative. Along with paintbrush, shapes and text, Tux Paint includes a "stamp" feature to add pre-drawn or photographic imagery to pictures, and a set of "magic tools" that provide filter effects (like blur, tint and waves) and interesting drawing tools (like train tracks, bubbles and grass). Tux Paint includes a collection of "starter" images, both coloring-book style and photo-realistic, and a large collections of stamps are available as a separate download. Additional content can be added by parents and teachers, or downloaded from 3rd parties. Tux Paint is available for Linux, BSD, Windows, Mac OS X and Haiku operating systems.
The Tool Command Language implementation
Tool Command Language (Tcl) is an interpreted language and very portable interpreter for that language. Tcl is embeddable and extensible, and has been widely used since its creation in 1988 by John Ousterhout. Bug reports to http://core.tcl.tk/tcl/ Follow code development at http://core.tcl.tk/tcl/
A planetarium software that shows a 3D simulation of the night sky
Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulae and others things like ground, landscape, atmosphere, etc.
The OpenGL Extension Wrangler Library is a simple tool that helps C/C++ developers initialize extensions and write portable applications. GLEW currently supports a variety of operating systems, including Windows, Linux, Darwin, Irix, and Solaris.
A portable, multi-platform, command-line driven graphing utility
A famous scientific plotting package, features include 2D and 3D plotting, a huge number of output formats, interactive input or script-driven options, and a large set of scripted examples.
Net-SNMP provides tools and libraries relating to the Simple Network Management Protocol including: An extensible agent, an SNMP library, tools to request or set information from SNMP agents, tools to generate and handle SNMP traps, etc.
Computer Algebra System written in Common Lisp
Maxima is a computer algebra system comparable to commercial systems like Mathematica and Maple. It emphasizes symbolic mathematical computation: algebra, trigonometry, calculus, and much more. For example, Maxima solves x^2-r*x-s^2-r*s=0 giving the symbolic results [x=r+s, x=-s]. Maxima can calculate with exact integers and fractions, native floating-point and high-precision big floats. Maxima has user-friendly front-ends, an on-line manual, plotting commands, and numerical libraries. Users can write programs in its native programming language, and many have contributed useful packages in a variety of areas over the decades. Maxima is GPL-licensed and largely written in Common Lisp. Executables can be downloaded for Windows, Mac, Linux, and Android; source code is also available. An active community maintains and extends the system. Maxima is widely used: annual direct downloads exceed 300,000. Many other users receive it through secondary distribution.
A universal instant messaging (IM) program
See https://pidgin.im/about/ for more information. Pidgin is an instant messaging program which lets you log in to accounts on multiple chat networks simultaneously. It runs on Windows, Linux, and other UNIX operating systems. Pidgin is compatible with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, MXit, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. It is written in C and makes heavy use of GLib and GTK+. Finch is a command line instant messaging program. It also lets you log in to accounts on multiple chat network simultaneously, and it is compatible with the same chat networks as Pidgin. It is written in C and makes heavy use of GLib and ncurses.
THIS SITE IS NO LONGER ACTIVELY MAINTAINED, FOR RECENT RELEASES, PLEASE GO TO: http://downloads.ghostscript.com/ For more information, please go to: http://www.ghostscript.com
Versatile Commodore Emulator
VICE is an emulator collection which emulates the C64, the C64-DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610). It runs on Unix, MS-DOS, Win32, OS/2, Acorn RISC OS, BeOS, QNX 6.x, Amiga, GP2X or Mac OS X machines.
An open source NES Emulator for Windows and Unix that features solid emulation accuracy and state of the art tools for power users. win32 autobuilds @ https://ci.appveyor.com/project/zeromus/fceux/build/artifacts
utility to split mp3, ogg vorbis and FLAC files without decoding
mp3splt is a free utility to split mp3, ogg vorbis and FLAC files without decoding, selecting begin/end time; if file is an album, you can get splitpoints automatically from internet or a local cue, cddb file. It also splits Mp3Wrap and AlbumWrap archives. Supports splitting and trimming by silence detection. For mp3 files, both ID3v1 and ID3v2 are supported using original tags or user defined tags.
Weak signal ham radio communication
The WSJT project currently includes five programs designed for amateur radio communication using state of the art digital techniques. Typical applications include meteor scatter, EME ("moonbounce"), and QRP communication at HF. Summary Program Descriptions: WSJT: Modes JTMS, FSK441, ISCAT, JT6M, JT65, JT4, Echo, CW. Optimized for meteor scanner, ionospheric scatter, and EME at VHF/UHF/Microwaves. WSJT-X: Modes JT65, JT9. Primarily for use at HF. MAP65: For EME an VHF and higher frequencies. Implements a panoramic, polarization-matching receiver for JT65. WSPR: Probe potential propagation paths using low-power transmissions. WSPR-X: Experimental version of WSPR, including the slow mode WSPR-15. Source code is maintained here SourceForge. For installable end-user packages please go to the WSJT web site at the link below.
Swiss army knife of image processing
GraphicsMagick provides a set of commandline tools and programming APIs for manipulating, editing, and converting raster and vector images. It is derived from ImageMagick, with the objective of providing better stability and performance than ImageMagick while retaining the original MIT/X11 license.
Doxygen is a JavaDoc like documentation system for C++, C, Java and IDL.
Grisbi is a very functional personal financial management program with a reasonable set of homefinance features.
Ettercap is a multipurpose sniffer/interceptor/logger for switched LAN. It supports active and passive dissection of many protocols (even ciphered ones) and includes many feature for network and host analysis. Development has been moved to GitHub, https://github.com/Ettercap/ettercap
NetHack is a popular single player dungeon exploration game that runs on a wide variety of computer systems.
The Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.
PyMOL is an OpenGL based molecular visualization system
PyMOL is a Python-enhanced molecular graphics tool. It excels at 3D visualization of proteins, small molecules, density, surfaces, and trajectories. It also includes molecular editing, ray tracing, and movies. Open Source PyMOL is free to everyone!
TightVNC is an improved version of VNC, great free remote-desktop tool. The improvements include bandwidth-friendly "Tight" encoding, file transfers in the Windows version, enhanced GUI, many bugfixes, and more.
Use Wine (Wine Is Not an Emulator) to run Windows applications on Darwin and Mac OS X.
CLISP is a portable ANSI Common Lisp implementation and development environment by Bruno Haible. Interpreter, compiler, debugger, CLOS, MOP, FFI, Unicode, sockets, CLX. UI in English, German, French, Spanish, Dutch, Russian, and Danish.
MSN compatible messenger application
A very nice MSN compatible messenger application, aMSN Messenger is a multiplatform MSN messenger clone. Works pretty much like its Windows based counterpart. Perfect for keeping in touch with those friends who have not yet seen the light. Works on linux