Our web component packages.
The @microsoft/fast-element library is a lightweight means to easily build performant, memory-efficient, standards-compliant Web Components. FAST Elements work in every major browser and can be used in combination with any front-end framework or even without a framework. To get up and running with @microsoft/fast-element see the Getting Started guide.
The @microsoft/fast-foundation package is a library of Web Component classes, templates, and other utilities intended to be composed into registered Web Components by design systems (e.g. Fluent Design, Material Design, etc.). The exports of this package can generally be thought of as un-styled base components that implement semantic and accessible markup and behavior.
This package does not export Web Components registered as custom elements - it exports parts and pieces intended to be composed into Web Components, allowing you to implement your own design language by simply applying CSS styles and behaviors without having to write all the JavaScript that's involved in building production-quality component implementations.
The @microsoft/fast-ssr package contains a NodeJS solution for rendering FAST templates and components. While primarily intended for supporting server-side rendering (SSR) scenarios, it also allows FAST to be used as a general purpose HTML templating solution.
The @microsoft/fast-router package contains a history-based navigation and routing solution designed around Web Components. By using fast-router, you can create multi-page and full application experiences. The router works with any Web Components, but has special support for Web Components built on FAST.
@fluentui/web-components is a library of Web Components that composes @microsoft/fast-foundation. @fluentui/web-components makes use of different stylesheets and may include components that specifically support Microsoft's Fluent design language.
The Fluent UI Web Components are built on @microsoft/fast-element and @microsoft/fast-foundation. The source for @fluentui/web-components is hosted in the Fluent UI monorepo.