This took a lot of serious math to execute. It's created by researchers at ETH Zürich's Flying Machine Arena, who took into account all the variables that go into flying a couple of little machines, balancing them, and perfectly coordinating their movements with each other.
Future Vision by Erwin Van Lun on this article
Robots will be everywhere! Every shape, every size. They will assist humanoid robots who will be our companions. Future robots of next generations quadcopters family can set up a whole festival terrain for thousand of visitors in just a few hours. Or build houses. Bridges. Or, even more imporant: dig tunnels under Africa spreading water all over the continent. Or to fly in other robots for a particular job. Whatever we want to achieve, we won’t need humans anymore. Not for the coordination, not for the man power. We only have to say what we want. Only our mind is our limitation. Not the future of tomorrow, but definitely of huge influence on mankind in the second half of this century.