Check: a unit test framework for C
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.
a parametric 3D CAD modeler
WARNING: FreeCAD has moved! FreeCAD code and release files are now hosted on github at https://github.com/FreeCAD/FreeCAD Only older files and code are available here. FreeCAD is a general purpose feature-based, parametric 3D modeler for CAD, MCAD, CAx, CAE and PLM, aimed directly at mechanical engineering and product design but also fits a wider range of uses in engineering, such as architecture or other engineering specialties. It is 100% Open Source and extremely modular, allowing for very advanced extension and customization. FreeCAD is based on OpenCasCade, a powerful geometry kernel, features an Open Inventor-compliant 3D scene representation model provided by the Coin 3D library, and a broad Python API. The interface is built with Qt. FreeCAD runs exactly the same way on Windows, Mac OSX and Linux platforms.
Run Windows applications on Linux, BSD, Solaris, and Mac OS X
Wine is an Open Source implementation of the Windows API on top of X and Unix. Wine provides both a development toolkit for porting Windows sources to Unix and a program loader, allowing many unmodified Windows binaries to run on x86-based Unixes.
gPhoto is a program and library framework that lets users download pictures from their digital cameras. The libgphoto2 library gives you access to hundreds of models of digital cameras on several platforms. GIT repo and Issue tracker lives at https://github.com/gphoto/ these days.
A comprehensive software suite for reading barcodes. Supports EAN/UPC, Code 128, Code 39, Interleaved 2 of 5 and QR Code. Includes libraries and applications for decoding captured barcode images and using a video device (eg, webcam) as a barcode scanner.
Open-source, free, multi-platform BASIC compiler, with syntax similar MS-QuickBASIC (including the GFX statements), that adds new features such as pointers, unsigned data types, inline assembly, a pre-processor and many others.
Pyton GnuPGInterface is meant to be a filehandle-concentrating Python interface to GnuPG, the GNU Privacy Guard. It has an API similar to the Perl module GnuPG::Interface.
Lazarus is a free and open source development tool for the Free Pascal Compiler. The purpose of this project is to serve as a Code Repository, Wiki Knowledgebase and support site for converting existing components and libraries to work with Lazarus and the Free Pascal Compiler.
A free COBOL compiler
GnuCOBOL (formerly OpenCOBOL) is a free COBOL compiler. cobc translates COBOL source to executable using intermediate C, designated C compiler and linker. OpenCOBOL 1.1 became GNU Cobol 1.1 in 2013. Official releases at ftp://ftp.gnu.org/gnu/gnucobol GnuCOBOL 2.2 is the last release, version 3.0 is on its way. A programmer's guide, by Gary Cutler, and other documentation, is indexed at http://open-cobol.sourceforge.net/ OpenCOBOL was written by Keisuke Nishida and Roger While, from 2001 to 2012. GnuCOBOL is also authored by Simon Sobisch, Ron Norman, Edward Hart, Sergey Kashyrin, Dave Pitts and Brian Tiffin. Others listed in the AUTHORS and THANKS files. Copyright 2001-2018 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the FSF; either version 3, or (at your option) any later version. The libcob run time support source tree is licensed LGPL.
Library to access MTP players (Mp3 players, Android Phones)
libmtp is a LGPL library implementation of the Media Transfer Protocol (MTP), a superset of the Picture Transfer Protocol (PTP).
Matroska is an open standard audio/video container format. Visit our homepage at http://www.matroska.org
A multi-platform software synthesiser emulating (somewhat inaccurately) pre-GM MIDI devices such as the Roland MT-32, CM-32L, CM-64 and LAPC-I. In no way endorsed by or affiliated with Roland Corp. Source hosted at: http://www.github.com/munt/
OpenLierox is an extremely addictive realtime worms shoot-em-up backed by an active gamers community. Dozens of levels and mods are available to provide endless gaming pleasure.
.NET C# USB library for WinUSB, LibUsb-Win32, and libusb-1.0. Using the common device classes, applications work with all operating systems and drivers without modification. Lots of example code. Open source software at sourceforge.net.
Library to control radio transceivers and receivers
The Hamlib project's purpose is to develop flexible and portable shared libraries that offer a standardized API to control any radio oriented equipment through a computer interface.
The ZZIPlib provides read access on ZIP-archives. The library uses only the patent-free compression-algorithms supported by Zlib. It provides functions that transparently access files being either real files or zipped files, both with the same filepath
FreeWRL is an Open Source, cross platform VRML2 and X3D compliant browser, with script, SAI and EAI support. Platforms supported: Linux and other Unix-style platforms; Mac OS/X; Windows. Support for mobile platforms (iOS, Android, QNX) is under development.
A multimedia framework based on Qt and FFmpeg
QtAV is a cross-platform and high performance multimedia playback framework based on Qt and FFmpeg. Features: timeline preview, gpu decoding etc
A PDF parsing, modification and creation library.
The PoDoFo library is a free, portable C++ library. It can parse and modify existing PDF files and create new ones from scratch. It also includes several tools to work with PDF files. It features an unique approach which provides access to PDF documents via an object tree. Therefore, PDFs can be created and or manipulated using a simple tree structure.
MeCab is a fast and customizable Japanese morphological analyzer. MeCab is designed for generic purpose and applied to variety of NLP tasks, such as Kana-Kanji conversion. MeCab provides parameter estimation functionalities based on CRFs and HMM
A set of libraries and utilities for reading Microsoft Access database (MDB) files.
OpenNX is an OSS drop-in replacement for Nomachine's nxclient.
libdmtx is a software library that enables programs to read and write Data Matrix (or "DataMatrix") 2D barcodes. It runs on several platforms, and can be accessed by multiple languages. The package provides fully featured command line utilities.
Java wrapper for 7z archiver engine
Native (JNI) cross-platform library to extract (password protected, multi-part) 7z Zip Rar Tar Split Lzma Iso HFS GZip Cpio BZip2 Z Arj Chm Lhz Cab Nsis Deb Rpm Wim Udf archives and create 7z, Zip, Tar, GZip & BZip2 from Java.