IUP Portable User Interface is described as 'IUP is a multi-platform toolkit for building graphical user interfaces. It offers a simple API in three basic languages: C, Lua and LED. IUP's purpose is to allow a program source code to be compiled in different systems without any modification' and is an app in the Development category. There are nine alternatives to IUP Portable User Interface for a variety of platforms, including Linux, Windows, Mac, Android and BSD. The best alternative is Qt, which is both free and Open Source. Other great apps like IUP Portable User Interface are GTK+ (Free, Open Source), wxWidgets (Free, Open Source), Uno Platform (Free, Open Source) and FLTK (Free, Open Source).
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.
GTK+ is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off tools to complete application suites.
wxWidgets is a C++ library that lets developers create applications for Windows, OS X, Linux and UNIX on 32-bit and 64-bit architectures as well as several mobile platforms including Windows Mobile, iPhone SDK and embedded GTK+.
Uno is the platform for building native mobile, desktop and WebAssembly apps with C#, XAML from single codebase. It's a Universal Windows Platform Bridge that allows UWP-based code (C# and XAML) to run on iOS, Android, and WebAssembly.
The Fast, Light Toolkit (FLTK, pronounced fulltick) is a cross-platform graphical user interface (GUI) library developed by Bill Spitzak and others. Made to accommodate 3D graphics programming, it has an interface to OpenGL, but it is also suitable for general GUI programming.
MauiKit is a framework based on QQC2 and Kirigami, that helps to create convergent applications that run on GNU Linux and Android, based on the Maui HIG. MauiKit is an open source framework to make the applications look good, made by...