Apps similar to CopperSpice include Qt, which is open source with a free version. Other options are Slint and Nevron Open Vision for .NET. In total there are three Software Frameworks like CopperSpice for Mac, Windows, Linux and the web.
Qt is a cross-platform application framework that is widely used for developing application software that can be run on various software and hardware platforms with little or no change in the underlying codebase, while having the power and speed of native applications.
Finland
EU
GUI toolkit for Rust, C++, and JavaScript to efficiently develop fluid graphical user interfaces for embedded devices and desktop applications.
GermanyEU
Nevron Open Vision for .NET is a suite of advanced UI components that helps you develop feature-rich Web (Blazor WebAssenbly) and Desktop (WinForms, WPF, Xamarin.Mac) applications from a single code base.
BulgariaEU
