On June 27, 2016 .NET Core 1.0 was finalized released for production. This was mentioned back in the fall when beta releases were released but it is now officially released.
This is a full version of .NET that is completely open sourced on github and available for windows, linux, and OS X. This is very exciting for .NET developers. .NET is is also available on Xamarin, which makes .NET available on Android and IOS.
Also, on top of this there is an additional setup of libraries that make ASP.NET Core to allow web develoment across all platforms.
With the release of a free full version of Visual Studio, this make the development of C# applications using a free IDE across all platforms possible!