wxWidgets - wxWidgets: Cross-Platform GUI Library
AfterShip - AfterShip is the shipment tracking API for ecommerce businesses and marketplaces.
Electron - Build cross platform desktop apps with web technologies
Cabubble - Taxi and minicab quotes for London, Birmingham, Manchester and throughout the UK. Book a licensed taxi or minicab online via website or mobile app.
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.
OnTime 360 - Cloud-based courier software with online order entry, route optimization, and dynamic tracking. The complete delivery software solution.