Open-source

• Gempyre – https://github.com/mmertama/Gempyre
• gtkmm – https://gtkmm.org/
• IUP – https://www.tecgraf.puc-rio.br/iup/
• JUCE – https://juce.com/
• NAppGUI – https://github.com/frang75/nappgui_src
• Nana – https://github.com/cnjinhao/nana
• U++ – https://www.ultimatepp.org/
• Wt – https://github.com/emweb/wt/