A PDF Reader and Note-taker for OS X
Skim is a PDF reader and note-taker for OS X. It is designed to help you read and annotate scientific papers in PDF, but is also great for viewing any PDF file. Skim requires Mac OS X 10.6 or higher.
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.
An extremely powerful and configurable BitTorrent client
Vuze (formerly Azureus) is an extremely powerful and configurable BitTorrent client. Search and download torrent files. Play, convert and transcode videos and music for playing on many devices such as PSP, TiVo, XBox, PS3, iTunes (iPhone, iPod, Apple TV).
An intranet chat application that does not require a server.
LAN Messenger is a p2p chat application for intranet communication and does not require a server. A variety of handy features are supported including notifications, personal and group messaging with encryption, file transfer and message logging.
Audio converter and CD ripper for various formats
fre:ac is a free audio converter and CD ripper for various formats and encoders. It features MP3, MP4/M4A, WMA, Ogg Vorbis, FLAC, AAC, and Bonk format support, integrates freedb/CDDB, CDText and ID3v2 tagging and is available in several languages.
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.
Simple but advanced disc burning for Mac OS X
Create data discs with advanced data settings. Create video and audio discs, Burn will convert if needed. Create DVD-Video discs. Recreate discs. Burn doesn't reinvent the wheel, it uses many powerful open source Unix utilities and is also open source.
Ham Radio Digital Modem Application
Fldigi is a modem program for most of the digital modes used by radio amateurs today: CW, PSK, MFSK, RTTY, Hell, DominoEX, Olivia, and Throb are all supported. It can help calibrate a sound card to a time signal and do frequency measurement tests. NOTICE: You must proceed to the Files section to locate the correct fldigi, flrig etal download for your particular operating system. Do not blithely use the big green Download button! Use the "Files" menu item or the "Browse All Files" link.
Panorama photo stitcher
With Hugin you can assemble a mosaic of photographs into a complete immersive panorama, stitch any series of overlapping pictures and much more.
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.
A very high quality package of printer drivers for CUPS on Linux, Macintosh OS X, and other POSIX-compliant operating systems. This project also maintains an enhanced Print plug-in for GIMP 2.x from the same code base.
Free project scheduling and management tool
GanttProject is a project scheduling application written in Java and featuring Gantt chart, resource management, calendaring, import/export (MS Project, HTML, PDF, spreadsheets). Learn more on http://ganttproject.biz
A cross-platform GUI library
wxWidgets is a C++ library that lets developers create applications for Windows, Mac OS X, Linux and other platforms with a single code base. It has popular language bindings for Python, Perl, Ruby and many other languages, and unlike other cross-platform toolkits, wxWidgets gives applications a truly native look and feel because it uses the platform's native API rather than emulating the GUI. It's also extensive, free, open-source and mature.
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.
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.
Real-time 3D visualization of space
Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects.
StepMania is a music/rhythm game. The player presses different buttons in time to the music and to note patterns that scroll across the screen. Features 3D graphics, visualizations, support for gamepads/dance pads, a step recording mode, and more! WE HAVE MOVED TO GITHUB.
OpenSource OpenGL Multiplayer Multiplatform Battle Zone capture the Flag. 3D first person tank game. Project has moved to Github: https://github.com/BZFlag-Dev/bzflag
Free and Open Source Browser based Security Framework
OWASP Mantra - Free and Open Source Browser based Security Framework, is a collection of free and open source tools integrated into a web browser, which can become handy for penetration testers, web application developers, security professionals etc.
Easy file synchronization for everyone
FullSync is a powerful tool that helps you keep multiple copies of various data in sync. I.e. it can update your Website using (S)Ftp, backup your data or refresh a working copy from a remote server. It offers flexible rules, a scheduler and more
Real-time interactive fractal zoomer
Real-time interactive fractal zoomer. Home Page: http://xaos.sf.net/ GitHub: - Source https://github.com/xaos-project/XaoS - Issues: https://github.com/xaos-project/XaoS/issues - Wiki: https://github.com/xaos-project/XaoS/wiki Discussion Groups: - Users: http://groups.google.com/group/xaos-users - Developers: https://groups.google.com/forum/#!forum/xaos-devel
Free church worship presentation software
Open Source Worship Presentation Software. This project has moved to Launchpad: https://launchpad.net/openlp
Java applications to control a model railroad layout.
Java interfaces and sample implementations for controlling a model railroad layout from a personal computer. JMRI is intended as a jumping-off point for hobbyists to build their own layout controls. Includes the DecoderPro and PanelPro applications.
An open source Mac OSX RSS reader with support for RSS/Atom feeds
Vienna is an open source Mac OSX RSS reader with support for RSS/Atom feeds, article storage and management via a SQLite database, written in Objective-C and Cocoa. Feeds can be accessed directly, or through a syncing service supporting the Open Reader API, like BazQux.com, FeedHQ.org, InoReader.com or TheOldReader.com. Development now happens on GitHub: https://github.com/ViennaRSS/vienna-rss
Smultron is a text editor written in Cocoa for Mac OS X Leopard 10.5 which is designed to be both easy to use and powerful.