This visualisation software shows all the moving aircraft on the planet at once. It lets you see them as tens of thousands of 3D objects, along with trails. It uses open data to get its information, and Shaders to speed up rendering. The planet textures are based on data from NASA:

White indicates high altitude, and red indicates low altitude. The heights are also ‘amplified’, because otherwise you would not be able to see the altitude against the diameter of the Earth!

Note that this software was written for a previous employer, which means I do not hold the licence, and cannot sell it myself.