Real-time entertainment services deployed over the open, unmanaged Internet – streaming audio and video – account now for more than 70% of the Internet traffic and it is assumed that this number will reach 80% by 2021. The technology used for such services is commonly referred to as HTTP Adaptive Streaming (HAS) and is widely adopted by various platforms such as YouTube, Netflix, Flimmit, etc. thanks to the standardization of MPEG-DASH and HLS. This talk will provide an overview of HAS, the state of the art of selected deployment options, and reviews work-in-progress as well challenges ahead. The main challenge can be characterized by the fact that (i) content complexity increases, (ii) delay or latency are vital application requirements, and (iii) Quality of Experience cannot be neglected anymore.