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.
Psi IM — Qt-based XMPP/Jabber client
Psi aims to be a feature-rich Jabber/XMPP client for novice and experienced Jabber users. There are builds available for MS Windows, GNU/Linux and macOS.
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 wrapper for the cross-platform, GUI API toolkit wxWidgets
A set of Python extension modules that wrap the cross-platform GUI classes from wxWidgets.
Rapid applications development tool and libraries for FPC
The Lazarus IDE is a stable and feature rich visual programming environment for the FreePascal Compiler. It supports the creation of self-standing graphical and console applications and runs on Linux, FreeBSD, MacOSX and Windows.
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.
Doxygen is a JavaDoc like documentation system for C++, C, Java and IDL.
A premier mind-mapping software written in Java
A mind mapper, and at the same time an easy-to-operate hierarchical editor with strong emphasis on folding. These two are not really two different things, just two different descriptions of a single application. Often used for knowledge and content management.
OpenEMR is an open source medical practice management application (EHR EMR PMS) featuring fully integrated electronic health records, scheduling, electronic billing, internationalization, free support, a vibrant community, and a whole lot more.
Cross platform GUI for Maxima
wxMaxima is a cross-platform graphical front-end for the computer algebra system Maxima based on wxWidgets. It provides nice display of mathematical output and easy access to Maxima functions through menus and dialogs.
3D game engine (more powerful redesign of the Cube engine) and FPS game
NetHack is a popular single player dungeon exploration game that runs on a wide variety of computer systems.
Another version of the simple action game modeled after the lightcycle sequence of the movie Tron.
Nagstamon is a Nagios status monitor which resides in systray or desktop (GNOME, KDE, Windows) as floating statusbar to inform you in realtime about the status of your hosts and services. It allows to connect to multiple Nagios based monitors. Currently supported are Nagios, Icinga, Opsview, Op5 Ninja, Check_MK Multisite, Centreon and Thruk.
An Open Source DOS emulator to run old DOS games
DOSBox emulates a full x86 pc with sound and DOS. Its main use is to run old DOS games on platforms which don't have DOS (Windows 7 / Windows Vista / Windows 2000 / Windows XP / Linux / FreeBSD / Mac OS X)
Double Commander is a cross platform open source file manager with two panels side by side. It is inspired by Total Commander and features some new ideas.
Free flexible open source todo manager featuring hierarchical tasks
Task Coach - Your friendly task manager. Task Coach is a free open source todo manager. It grew out of frustration about other programs not handling composite tasks well. In addition to flexible composite tasks, Task Coach has grown to include prerequisites, prioritizing, effort tracking, category tags, budgets, notes, and many other features. However, users are not forced to use all these features; Task Coach can be as simple or complex as you need it to be. Task Coach is available for Windows, Mac OS X, and GNU/Linux; and there is a companion iOS app.
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.
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!
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.
DjVu is a web-centric format for distributing documents and images. DjVu was created at AT&T Labs-Research and later sold to LizardTech Inc. DjVuLibre is a GPL implementation of DjVu maintained by the original inventors of DjVu.
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 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.
Repository of desktops and programs for the Cygwin platform
A large repository of open-source programs built for Cygwin, including X11 desktops, language interpreters, multimedia frameworks, cross-compiler toolchains, and much more. Also hosted here is the cygport tool for building Cygwin packages. cygport releases and the Ports Git repositories are hosted here; Ports packages are available from the website.
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.