A free IDE for C#, VB.NET, & Boo projects on Microsoft's .NET platform
SharpDevelop is the open-source IDE for the .NET platform. Write applications in languages including C#, VB.NET, F#, IronPython and IronRuby, as well as target rich and reach: Windows Forms or WPF, as well as ASP.NET MVC and WCF. It starts from USB drives, supports read-only projects, comes with integrated unit and performance testing tools, Git, NuGet and a lot more features that make you productive as a developer.
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.
smart and open source document management system
LogicalDOC is both document management and collaboration system. The software is loaded with many functions and allows organizing, index, retrieving, controlling and distributing important business documents securely and safely for any organization and individual. Gone are the days when companies used paper-based processes such as printing, mailing and manual filing of paper documents; our document management system replaces all of this with electronic procedures that allow your organization to reduce costs significantly. Check out https://www.logicaldoc.com to learn more. The design of LogicalDOC is based on best-of-breed Java technologies in order to provide a reliable DMS platform. The main interface is web-based, no need to install anything else; users can access the system through their browser. LogicalDOC CE is 100% free software and is packaged with an open source database; while it supports all major DBMS, developers still recommend MySQL for production systems.
ArahPaint4 - program for drawing images in repeat mainly intended for textile design (jacquard) - supports different X:Y aspect ratio - layers - unlimited undo - works fast with large images - seamless drawing in repeat - advanced textile filters - integrated image browser
An eMule client that is based on the original one, but with a new credit system.
EOS is a library that allows automated XML marshalling/demarshalling of Pascal Business Objects and complex object structures and it's easy linking to the GUI through the ModelBridge framework. You can use it with Delphi, Kylix and Free Pascal.