Much of the potential of the IoT will be realised through value-added services, but this is being held back by fragmentation and limited interoperability. W3C is addressing this through developing web standards for things that decouple applications from the underlying IoT technologies. Applications will no longer need to be developed around the details of the myriad IoT technologies and standards. This means that developers can create applications more easily, with less effort, especially, when combining IoT devices from different ecosystems. W3C’s standards further enable suppliers and consumers of services to agree on the meaning of the data they exchange through rich semantic descriptions of the kinds of things, their capabilities and relationship to the environment in which they reside. This is based upon W3C’s framework for graph data and paves the way to the emergence of the Sentient Web – ecosystems of services with awareness based upon sensors, and reasoning based upon graph data and rules, together with graph algorithms and machine learning.