fyne-io/fyne

Fyne is a GUI (graphical user interface) toolkit written in Go, meaning it gives you the building blocks to create desktop and mobile apps with buttons, windows, labels, and other visual elements. The key appeal is that you write your app once and it runs across desktop and mobile platforms from the same codebase. The README includes a short, illustrative code example: a few lines of Go create a window with a label and a button that changes the text when clicked. This captures the design goal, minimal boilerplate to get a working visual app. From there you can package the same code for Android or iOS using the included fyne command-line tool, which handles the platform-specific packaging steps. The toolkit is inspired by Material Design (a visual design system) and comes with a built-in light and dark theme. It ships with a widget demo you can run immediately to see the full set of available UI components. Apps built with Fyne don't require pre-installed libraries on the user's machine, which makes them easier to distribute. You would use Fyne when you want to build a cross-platform desktop or mobile app in Go without needing separate native UI frameworks for each platform. It requires Go version 1.17 or later, a C compiler, and your system's standard development tools. Topics include go, android, and ios, confirming the mobile targets. Building the app for the first time on some systems can take several minutes.