Open Source User Interface (UI) Software

Kivy is an open source, cross-platform UI framework that lets you develop applications that make use of innovative, multi-touch user interfaces. Written in Python with a graphics engine built over OpenGL ES 2, Kivy supports various input devices and protocols, and gives you access to over 20 widgets that are all highly extensible and have built-in multi-touch support. You can run the same codebase on Mac, Windows, Linux, Android and iOS. Kivy is 100% free and open source with a professionally developed and used toolkit, as well as a stable framework and well-documented API, so you can be confident in using it in a commercial product.

Avalonia is a cross-platform UI framework for dotnet, providing a flexible styling system and supporting a wide range of Operating Systems such as Windows, Linux, macOS. Avalonia is mature and production-ready. We also have in beta release support for iOS, Android and in early stages support for browsers via WASM. Avalonia is open source, free to use, and always will be. Clone the source today to dig deeper. The free VS extension provides everything needed to start, including a XAML previewer. JetBrains deep understanding of Avalonia shines through with rich Rider and R# support. Deploy to the platforms you care about with ease. Leverage existing knowledge, code and packages to kickstart your project. Get the support your project needs with one of our commercial support agreements. Help you can count on. JetBrains delivers huge productivity gains for Avalonia developers.

CSS-Vise A lightweight, minimal and mature vanilla CSS framework built with care. It can be used as a primary framework or as a secondary one alongside any other framework .Check this demo page for a quick showcase http://appforgelab.com/vise Why Vise ? There is dozens of CSS frameworks available but why Vise ? - You may not need a heavy framework to build a great user experience. - You may want to use more than one framework on the same HTML document. - You may want a smarter and easier to learn minimal framework. - You need a library that is supported by 98% of web browsers. For docs and more visit Vise's github repository https://github.com/Appforge-lab/CSS-Vise

JUCE is a C++ toolkit for building cross-platform applications on PC/Mac/Linux/iOS/Android. Particularly good for complex, customised GUIs and audio/midi processing, it also includes a vast range of classes to help with all your day-to-day programming tasks.

Semantic UI is a development framework that lets you create beautiful, custom and responsive website layouts using human-friendly HTML. The syntax used is based on natural language, so concepts are linked intuitively. Semantic UI utilizes concise HTML, intuitive JavaScript and simplified debugging, making front-end development an absolute dream for developers. Semantic UI is partnered with popular frameworks React, Angular, Meteor, Ember and many others so you can easily integrate it and organize your UI layer with your application logic. Semantic UI comes with over 3,000 high level theming variables and just about every layout option you can think of, giving you complete design freedom. It also has over 50 UI components enabling you to build your entire site with just one stack and share your UI between a number of different projects.

Hummingbird is a component system for Tailwind developers who care about architectural discipline. It ensures global design control with local utility flexibility. Hummingbird is a lightweight, framework-agnostic tool that integrates seamlessly with modern stacks and helps build scalable, maintainable web applications without extra weight.