The smallest header-only GUI library(4 KLOC) for all platforms
Dynamic Extension for TCL/TK
Turn Python command line programs into a full GUI application
A small C library for building user interfaces with C, XML and CSS
A simple, friendly framework for Free Pascal text mode GUI creation.
Free texture packer
OpenNum lets you distribute solvers with a nice graphical interface
A web UI client for managing git repos on the go
iOS Automation Framework iOS Touch Simulation Library
GUI App for creating study folders inside a drive in a structured way
Python bindings for the Chromium Embedded Framework (CEF)
Garnet Common Lisp GUI Library
Marathon supports testing of Java/Swing and Java/Fx applications.
Light & Dark Vim color schemes inspired by Google's Material Design
A Simple ADB (Android Debug Bridge) Command Execution GUI for Windows.
Build cross platform HTML desktop apps on .NET
A C# Control use to edit RTF can replace RichTextBox.
Visual Docker Container Management on Mac & Windows
Make yourself a GUI for DOS from QBasic
AVR simulator IDE
GUI for updating PDF bookmarks using PDF Toolkit (PDFtk) on Windows