Racket GUI library · MIT · Qt 6 · Three platforms

Real Qt widgets. Written in Racket.

Bezel binds Qt Widgets to Racket through a small, validated C ABI. Write your application in Racket, style it with QSS, and ship self-contained packages on Windows, macOS, and Linux.

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Bezel showcase — real Qt widgets rendered headlessly from Racket

Why Bezel

racket/gui is hard to style. Web shells trade away native feel.

Real Qt widgets

Windows, buttons, inputs, lists, tables, trees, tabs, menus, dialogs, layouts — professional-tools UI on Qt Widgets.

QSS styling

Qt's CSS-like styling system on every window — make it look like your product, not like a demo.

Thread-safe by design

Public widget calls from any Racket thread marshal to the GUI thread; timers marshal back automatically.

Agent-friendly verification

widget-grab-png renders real widgets to PNG; CI runs headlessly with Qt's offscreen backend.

Self-contained packages

libbezel, the Qt runtime, and plugins are embedded — end users install with raco pkg install, nothing else.

Ship real applications

raco bezel package produces distributable app folders, installers, signing helpers, and silent self-update.

How it compares

A third path, over Qt Widgets.

A stable C ABI sits under Qt Widgets; the Racket layer on top handles GUI-thread marshaling, signals, lifetime rules, and generated bindings.

	Bezel	racket/gui	Web-based shells
UI toolkit	Qt Widgets (native)	custom-drawn widgets	HTML in a WebView
Styling	QSS	limited, hard to modernize	full CSS
App language	Racket	Racket	Rust or JS/Node
Native look & feel	real OS widgets	custom look	DOM widgets
User installation	runtime bundled, nothing extra	Racket distribution	WebView or bundled Chromium

Quick start

Two commands to a real Qt window.

terminal

# grab the matching zip from GitHub Releases, then:
$ raco pkg install --auto --name bezel-lib bezel-lib-windows-x86_64.zip

# verify the native runtime end to end
$ raco bezel doctor
✓ windows-x86_64 · Qt runtime bundled · ABI verified

hello.rkt

#lang racket/base
(require bezel)

(make-application #:name "Hello Bezel")

(define count (make-label "Clicked 0 times"))
(define btn   (make-button "Click me"))

(connect! btn "clicked()"
          (lambda (_)
            (widget-set-text! count "Clicked!")))

(define win (make-window #:title "Hello Bezel" #:size '(320 140)))
(layout! win (vbox count btn))
(run win)

Requirements. Racket 8.0+ on a supported release target — Linux x86_64, Windows x86_64, macOS Apple Silicon. Bezel is MIT licensed; redistributed Qt keeps its own license terms.