Open Source

ASP.NET MVC, Web API, and Web Pages (Razor) are Open Source Projects

The source code ASP.NET MVC, Web API, and Web Pages are released under Apache 2.0 license. You can download the code from our Git repository at, watch code check-ins as they’re made, and see what’s being planned on the public roadmap.

Additionally, these projects are able to accept community contributions, including pull requests. Some example community contributions are the planned inclusion of cross-origin resource sharing (CORS) support in ASP.NET Web API and Attribute Routing in ASP.NET MVC.

ASP.NET continues to be fully supported by Microsoft. These products are actively developed by the ASP.NET team assigned to the Microsoft Open Tech Hub and in collaboration with a community of open source developers. Together we are dedicated to creating the best possible platform for web development.

ASP.NET is part of a great open source .NET community

The .NET open source community is doing some amazing things! We’re of course excited about ASP.NET, but we want you to know that the community is producing some great alternative frameworks as well. We’ve listed some top projects in a few open source content sections on this site, e.g. other MVC frameworks in our ASP.NET MVC Open Source tab and service frameworks in the ASP.NET Web API Open Source tab.

In order to make it easier to leverage community web frameworks in ASP.NET, we’re getting behind the Open Web Interface for .NET (OWIN) standard. OWIN has gained popularity in the community as a platform for hosting .NET on web servers. There are times when people want to host ASP.NET Web API, ASP.NET SignalR and more outside of IIS or without System.Web using SelfHost. OWIN allows our frameworks to be written in a way that they can easily be hosted on IIS, HTTP.SYS, or even through the command line. This new hosting stack will allow us to host ASP.NET with a much smaller memory footprint and is expected to improve performance compared to the existing SelfHost solution we have today. Additionally, this will let you mix and match services and frameworks much more easily.

May 14, 2013