DotNetNuke is an open source platform for building web sites based on Microsoft .NET technology.

It is written in VB.NET and distributed under both a Community Edition BSD-style license ^[3] and a commercial proprietary license. DotNetNuke's content management system is extensible and customizable through the use of skins, modules, data providers, language packs and templates.

The DotNetNuke Corporation is the steward of the DotNetNuke open source project. The open source version of DotNetNuke is called the Community Edition and is available for free download on CodePlex. The Community Edition includes access to the source code of the framework and standard installation modules, and an MIT license ^[3] allowing flexible modification and distribution rights. The Community Edition is a popular web content management (WCM) system and application development framework for ASP.NET, with over 6,000,000 downloads and 600,000 production web sites as of October 2010.