Project Wing is a Google X research project that is focusing on the development of a drone-based delivery system that uses autonomous drones. The drones would be able to deliver packages when and where they're required.
Project Wing has been in development for around two years, according to Google. Test flights were recently conducted in Australia that involved a winged shuttle-shaped drone taking off vertically using four front-mounted propellers, before navigating its way -- fully autonomously -- to a preset location. The drone hovered above the treeline and gently lowered a package to the ground before cutting off its attachment to the package and reeling its cord back in before returning home.
Don't expect to see any drones hovering above your front lawn and delivering your packages just yet though; Project Wing is still in the testing and prototyping phase and is not expected to result in a full-fledged delivery drone for years.