Fluent UI Blazor v5: the demands of a Microsoft project

Fluent UI Blazor v5 is more than a collection of UI components. Used by .NET Aspire, this new generation also illustrates the technical and organisational requirements needed to build a sustainable open source project at Microsoft.

In this session, we'll explore its architecture, from Razor components to the new Web Components. We'll see how configurable defaults, localisation, cultures and themes let you adapt the library to an application's needs.

Accessibility will take centre stage: keyboard navigation, focus management, semantics and contrast are not options, but essential design and validation criteria.

We'll also go behind the scenes of the project: security, code reviews, maintainer responsibilities, dependency tracking, repository synchronisation, automated testing, validation pipelines and package publishing. These practices guarantee quality, traceability and trust throughout development.

Finally, we'll present the Fluent UI Blazor MCP server, which makes component documentation and metadata directly usable by development assistants. A concrete deep dive into the practices that turn a UI library into a reliable open source product.