AfterShip - AfterShip is the shipment tracking API for ecommerce businesses and marketplaces.
wxWidgets - wxWidgets: Cross-Platform GUI Library
Digital Waybill - Digital Waybill is an online delivery ordering courier software solution that provides features & functions to help manage online ordering, GPS tracking and more.
Electron - Build cross platform desktop apps with web technologies
OnTime 360 - Cloud-based courier software with online order entry, route optimization, and dynamic tracking. The complete delivery software solution.
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.