While the modern programming language Haxe is well-known in some circles, many developers have never heard of it. Yet since it first appeared in 2005, it's been battle-tested by its loyal---if rather quiet---following. It boasts a pragmatic and mature combination of features for development in business, gaming, and even academic contexts.
MonoDevelop enables developers to quickly write desktop and web applications on Linux, Windows and Mac OS X. It also makes it easy for developers to port .NET applications created with Visual Studio to Linux and Mac OS X maintaining a single code base for all platforms.
RenderDoc is a free MIT licensed stand-alone graphics debugger that allows quick and easy single-frame capture and detailed introspection of any application using Vulkan, D3D11, OpenGL & OpenGL ES or D3D12 across Windows 7 - 10, Linux, or Android.