F# Functional App Development, using declarative dynamic UI

Never write a ViewModel class again! Conquer the world with clean dynamic UIs!

Fabulous allows you to combine the power of functional programming and the simple Model-View-Update architecture to build any kind of mobile and desktop applications with an expressive, dynamic and clean UI DSL. Go cross-platform with Fabulous for Xamarin.Forms and target iOS, Android, Mac, WPF and more!


See also the goals for the future of Fabulous v2.

About Fabulous

Fabulous aims to provide all the tools to let you create your own mobile and desktop apps using only F# and the Model-View-Update architecture (shorten to MVU), with a great F# DSL for building dynamic UIs.
The combination of F# and MVU makes for a great development experience.

Note that Fabulous itself does not provide UI controls, so you’ll need to combine it with another framework like Xamarin.Forms.

Fabulous for Xamarin.Forms

Fabulous for Xamarin.Forms combines both frameworks with a tailored DSL to let you take advantage of everything Xamarin.Forms has to offer while keeping all the benefits of Fabulous.

With Fabulous for Xamarin.Forms, you will be able to write complete applications in F# like this:

type Model = { Text: string }
type Msg = ButtonClicked

let init () = { Text = "Hello Fabulous!" }

let update msg model =
    match msg with
    | ButtonClicked -> { model with Text = "Thanks for using Fabulous!" }

let view model =
        NavigationPage() {
                VStack(spacing = 16.) {
                    Image(Aspect.AspectFit, "fabulous.png")
                    Button("Click me", ButtonClicked)