openDesktop.org - The website openDesktop.
Microsoft Visual Studio - Microsoft Visual Studio is an integrated development environment (IDE) from Microsoft.
SourceForge - The Complete Open-Source and Business Software Platform.
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
Freecode - Freecode (formerly known as Freshmeat) is one of the legit open source development platforms that will be the key for developers and programmers to have a streamlined process via having enhanced collaboration and coding leverages.
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.