Umbraco CMS is a free and open source .NET content management system, released under the MIT licence, for .NET developers and editorial teams who need to build and operate content-managed websites on infrastructure they control.

What it is

Umbraco CMS is a content management system written in C#, living in the .NET and ASP.NET Core ecosystem and distributed as the NuGet package Umbraco.Cms. It ships a backoffice editing interface alongside the runtime, so a single application serves both editorial authoring and content delivery. The repository carries the topics asp-net-core, cms, csharp, dotnet-core, umbraco and umbraco-cms, and the project describes its mission as making Umbraco "friendly, simpler and social" in service of digital experiences. Development is community-driven, with a contributing guide, an issue tracker, a discussion area for feature requests and the hacktoberfest topic marking it as an open contribution target.

The concrete problem it solves is the absence of a maintained, licence-free content layer for .NET web applications. Rather than cloning this repository and building from source, teams install a project template and get a running CMS: the README states plainly that Umbraco should not be run from the source code found in the repository, and that the supported path is to install the packaged release and then extend it. In place of a hand-built content model, editing UI and persistence layer, it provides those pieces as a redistributable NuGet dependency that a .NET project references and configures.

Key capabilities

• Scaffolds a working CMS project from a .NET template via dotnet new install Umbraco.Templates followed by dotnet new umbraco --name MyProject.
• Distributed as the NuGet package Umbraco.Cms, so it is consumed as a dependency rather than vendored source.
• Runs on Windows, Linux and macOS, requiring the .NET Runtime and SDK.
• Provides a backoffice editing UI, previewable live at backofficepreview.umbraco.com, which is deployed automatically from the main branch, runs on mock data and does not support persistent edits.
• Extensible by design; the README states that Umbraco "is extremely extensible and can do whatever you need".
• Documented from fundamentals through to production deployment at docs.umbraco.com/umbraco-cms, including installation, an orientation guide and website tutorials.
• Licensed under MIT, with contribution entry points through CONTRIBUTING.md, GitHub issues and GitHub discussions.

Who uses it and how

• .NET developers on any of the three supported desktop platforms who install the template, run the generated project and extend it with custom code.
• Editorial and content teams that work in the backoffice UI while developers maintain the underlying ASP.NET Core application.
• Evaluators and prospective adopters who inspect the hosted backoffice preview before committing to an install, accepting that the preview uses mock data.
• Self-hosting teams that follow the deployment documentation to move an installation into production.
• Contributors and operators seeking community support through the Umbraco Discord server and the dedicated forum at forum.umbraco.com.

Getting started

Install the .NET Runtime and SDK, then run dotnet new install Umbraco.Templates, dotnet new umbraco --name MyProject, cd MyProject and dotnet run. The README points to the installation documentation for the full setup path.

How it compares

No comparable tools and no paid products are named in the supplied facts, so Umbraco CMS stands alone in this registry rather than being contrasted against alternatives. Comparisons on licence, hosting model or cost should be drawn from sources outside these facts.

When to use it — and when not to

Choose it when a .NET and ASP.NET Core stack is already in place and a permissively licensed CMS with an editing backoffice is wanted. A self-hoster must provision a .NET runtime and host the application; the README does not document database, storage or mail requirements, so operational planning has to start from the documentation site rather than the repository. Avoid it if the team does not work in .NET or wants a managed hosted product, and respect the README warning against running the CMS from repository source. The 525 open issues indicate a substantial active backlog, and support flows through community channels rather than a vendor commitment stated in the repository.

dotnet new install Umbraco.Templates
dotnet new umbraco --name MyProject
cd MyProject
dotnet run