I hadn't, until I came across the video clips below. According to Wikipedia:
Free running is a form of urban acrobatics in which participants, known as free runners, use the city and rural landscape to perform movements through its structures. It incorporates efficient movements from parkour, adds aesthetic vaults and other acrobatics, such as tricking and street stunts, creating an athletic and aesthetically pleasing way of moving. It is commonly practiced at gymnasiums and in urban areas that are cluttered with obstacles.
The term free running was coined during the filming of Jump London, as a way to present parkour to the English-speaking world. However, free running and parkour are separate, distinct concepts — a distinction which is often missed due to the aesthetic similarities. Parkour as a discipline emphasizes efficiency, whilst free running embodies complete freedom of movement — and includes many acrobatic maneuvers. Although the two are often physically similar, the mindsets of each are vastly different. The founder Sébastien Foucan defines free running as a discipline to self development, following your own way.
The video clips below show the recent World Championships of free running, held in Trafalgar Square, London, England. First is an overview of the Championships as a whole.
Next, here's footage of the World Champion, Tim Shieff, during his medal-winning performance.
I can't help but wonder whether Mr. Shieff has ever considered taking up traditional gymnastics. With his strength, grace and smoothness, I think he'd be gold medal material at the next Olympic Games!