This paper reports on the latest developments in tiled streaming. As an extension of HTTP adaptive streaming, it retains all the benefits of this streaming technology, while adding the potential of interaction when UHDTV is consumed on mobile devices. In particular, we discuss the underlying principles and aspects, such as multi-layer resolution scaling, spatial segmentation and adaptive streaming. Then we present insights from a number of technology validation tests and demonstrations, such as a live dance performance in Manchester in May 2013; a training tool for professional skiers employing tiled streaming in Schladming, host of the Alpine Skiing World Championship 2013; and tests incorporating `augmented reality'-style overlays in an athletics stadium in preparation for a trial at the 2014 Commonwealth Games. Finally, we report on the status of on-going standardization efforts in the MPEG-DASH ad-hoc group, where tiled streaming is considered as a new feature, referred to as Spatial Relationship Description.