If the Vikings had WebRTC, we'd all be speaking Danish. Battlefield communication in ancient warfare was primitive at best. The times of the Norse Gods were no different. They had trumpeters who would play a note, which you would recognize as your unit. Then a second set of notes that would tell your unit what to do. You had drums whose beat could change. That change would tell you to increase your pace or turn right. This all could be very confusing. The fog of war and the rattle of battle was a very real problem. Communication was tough.
With WebRTC, Viking Kings like Ragnar Lothbrok would have had access to the power of secure voice, video and data communications. But I promise you, WebRTC is like no other HTML5 API you've ever seen. To architect a successful WebRTC solution is to bring together an alliance of both networking and web technologies. When that alliance is understood, the result is a powerful platform for communication at your fingertips.