DotNetNuke is an open source platform for building web sites based on Microsoft .NET technology. DotNetNuke is written in VB.NET and distributed under both a Community Edition BSD-style license and a Professional Edition proprietary license. DotNetNuke's content management system is extensible and customizable through the use of skins, modules, data providers, language packs and templates.
Easy to Install – You can have the DotNetNuke web content management system (WCM or CMS) and application development platform up and running within minutes. Just download the software and follow the simple installation instructions. In addition, several hosting companies offer DotNetNuke-specific hosting packages, which include the tools and support to make project set-up even easier.
Easy to Use – The DotNetNuke content management system makes it easy for administrators, content editors, developers, and designers to manage all aspects of their web assets. Wizards, content-sensitive help, and a well-researched user interface provide a smooth user experience.
Powerful – The DotNetNuke content management system can support multiple web sites from a single application installation. By dividing administrative tasks between host level and individual site level, administrators can manage an unlimited number of websites – each with its own unique appearance and content.
Feature-rich – The DotNetNuke application comes loaded with a set of built-in features that provide exceptional functionality. Site hosting, web design, content management, security, and membership options are all easily managed and customized through simple, browser-based tools.
Localized – DotNetNuke includes a multi-language localization feature that allows administrators to easily translate their sites into any language. And with an international group of hosts and developers working within the DotNetNuke ecosystem, native support is always close at hand.
Leading-edge – The DotNetNuke web content management system and application development platform gives developers the opportunity to leverage best-practice software development concepts and leading-edge technologies like ASP.NET 2.0, Visual Studio, SQL Server, Windows Server, and IIS.
Flexible and Extensible – The DotNetNuke web content management system and application development platform fits easily into existing computing environments. The core framework includes a series of open APIs that make integration with existing applications simple and straightforward, allowing businesses to focus on extending features and functionality rather than troubleshooting installations. And, DotNetNuke is flexible enough to be used for anything — new applications, minor site modifications, major overhauls, and swap outs.
Recognized – The DotNetNuke web content management system and application development platform is widely recognized and respected in the open source community, with hundreds of thousands of applications in use. DotNetNuke Corp. and DotNetNuke community members continue to evolve the software through rigorous development, testing, community participation, real-world trials, and end-user feedback.
Conclusion
All i would say is, DNN is a very easy to develope platform page, as editing, adding content & module is so easy. But, due to its nature using Microsoft's ASP net & Ms Sql/Sql Express nature, i personally don't like this about DNN. Another drawback is, it is nowhere near as good as other CMS such as Wordpress, or etc as developement for this CMS are really slow. However, i really like the face that DNN standard packages comes with all available sources already without the need to install any 3rd party extensions.