Summary of some Annoucements:
Over the coming months, we will be open sourcing the full server-side .NET Core stack, from ASP.NET 5 down to the Core Runtime and Framework, and the open source .NET will be expanded to run on Linux and Mac OS X in addition to Windows.
Visual Studio Community 2013 is a new, free and fully featured edition of Visual Studio, available today, with access to the full Visual Studio extensibility ecosystem and support for targeting any platform, from devices and desktop to web and cloud services.
SOURCE: http://blogs.msdn.com/b/somasegar/archive/2014/11/12/opening-up-visual-studio-and-net-to-every-developer-any-application-net-server-core-open-source-and-cross-platform-visual-studio-community-2013-and-preview-of-visual-studio-2015-and-net-2015.aspx