Orchard CMS is an open-source .NET content management system from the ASP.NET ecosystem whose modern version, Orchard Core, is built on ASP.NET Core under the BSD-3-Clause license, with 8K+ GitHub stars and 2.4M+ NuGet downloads, ideal for .NET teams building content sites and applications.
DNN (DotNetNuke) is an open-source .NET CMS that originated in 2002, deeply integrated with the Microsoft stack, with built-in native multilingual support and granular permissions, plus 1000+ extensions in its marketplace, ideal for enterprise portals and intranets.
Umbraco is an open-source .NET CMS founded in Denmark in 2005 with over 700,000 installations, known for its MIT-licensed core, friendly editing experience and Heartcore headless mode for Microsoft-stack enterprise content sites.
Kentico is an all-in-one Digital Experience Platform (DXP) founded in Brno, Czech Republic in 2003. Built on the .NET stack, it combines CMS, digital marketing and e-commerce, serving 1000+ enterprise customers and suiting mid-to-large enterprises seeking integrated digital experiences.