A simulation engine is a powerful tool that provides realistic approximations of physical systems. With maple-sim, we integrate the open-source Java rigid-body dynamics engine, dyn4j, capable of ...
XAML Studio is a developer tool that can be used to prototype ideas before adding them to the rest of the application in Visual Studio.
If Windows is your preferred operating system, consider these open-source apps. There are numerous open-source apps available for almost any task. These are all free to install and use on Windows.