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1.14.1 • Public • Published

Uno/UX core

AppVeyor build status Travis CI build status NPM package License: MIT Slack Financial Contributors on Open Collective

Welcome to Uno, the core component in Fuse Open, a native app development tool suite.


npm install @fuse-open/uno

This will install the uno command and core libraries.


We're here to help Fuse Open development by building and maintaining several related pieces of core technology.

  • Cross-platform tools for building and running applications
  • Core libraries and platform abstraction
  • Uno programming language and compiler
  • Uno project format and build engine
  • UX markup language and compiler
  • Uno/UX test runner

Uno is used on Linux, macOS and Windows, and makes native apps for the following platforms:

  • Android
  • iOS
  • Linux (native)
  • macOS (native or Mono)
  • Windows (native or .NET)

Uno syntax

class App : Uno.Application
    public App()
        debug_log "Hello, world!";

The Uno programming language is a fast, native dialect of C# that can cross-compile to any native platform (in theory), by emitting portable C++14 for mobile or desktop platforms, or CIL bytecode for desktop platforms (Mono/.NET) — designed for developing high-performance UI-engines, platform abstractions or integrations, and other kinds of software traditionally required written in native C/C++.

Access all APIs and features on the target platforms directly in Uno — add a snippet of foreign code, and our compiler automatically generates the glue necessary to interoperate (two-way) with a foreign language. The following foreign languages are supported:

Run-time features

  • Memory in Uno is managed semi-automatically by automatic reference counting, avoiding unpredictable GC stalls.
  • Real generics – sharing the same compiled code in all generic type instantiations, without boxing values, and with full run-time type system support – avoiding exploding code-size and compile-times (while still being fast).
  • (Opt-in) reflection on all platforms – to dynamically create objects and invoke methods based on type information only known at run-time – enabling high-level Fuse features such as live-previewing UX documents.

See https://fuseopen.com/docs/ for more information about the Uno/UX (and JavaScript) stack.

Build instructions

Please read the build instructions for details on how to build the source code.


Please read the configuration reference documentation for details on how to set up uno's configuration files for your build-environment.

Command Line Reference

Please read the command-line reference documentation for details on how to use uno's command-line interface.


Please read CONTRIBUTING for details on our code of conduct, and the process for submitting pull requests to us.

Reporting issues

Please report issues here.


Code Contributors

This project exists thanks to all the people who contribute. [Contribute].

Financial Contributors

Become a financial contributor and help us sustain our community. [Contribute]



Support this project with your organization. Your logo will show up here with a link to your website. [Contribute]


npm i @fuse-open/uno

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