It's relatively easy to develop a drone that can fly on its own, but it's another matter developing one that can navigate the many obstacles of real life. That's where Microsoft thinks it can help. It just published an open source simulator, the Aerial Informatics and Robotics Platform, that helps designers test and train autonomous machines in realistic conditions without wrecking expensive prototypes. The tool has vehicles move through randomized environments filled with the minutiae you see on a typical street, such as power lines and trees -- if your drone can't dodge a tree branch, you'll find out quickly. You can see what the vehicle would see (including simulated sensor data), and the software ties into both existing robotic hardware platforms and machine learning systems to speed up development.