Agar is described as 'Modern open-source, cross-platform toolkit for graphical applications implemented in C, C++ and Ada (with bindings to other languages in development). Designed for ease of integration, it follows the philosophy of building the GUI around the application and not the' and is an app in the development category. There are more than 10 alternatives to Agar for a variety of platforms, including Windows, Linux, Mac, BSD and Android apps. The best Agar alternative is Qt, which is both free and Open Source. Other great apps like Agar are Qt Creator, GTK, wxWidgets and Avalonia UI.