Fluid - Turn Your Favorite Web Apps into Real Mac Apps.
wxWidgets - wxWidgets: Cross-Platform GUI Library
WebCatalog - Run your favorite web apps natively
Electron - Build cross platform desktop apps with web technologies
Web2Desk - Web2Desk is a tool to convert your favorite websites to Desktop app in just one click.
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.