The Semantic Web is about creating a global machine-processable Web based on innovative mechanisms to publish, access, manage, use, and integrate the large amounts of data available. Despite promising developments at the technological and outreach levels, a number of challenges, most prominently the openness, dynamics, scale and heterogeneity of the (Semantic) Web environment, still hamper the realization of this vision. Moreover, various other trends around the Internet make semantic data become more and more ubiquitous, adding a new dimension to this problem. The Internet of Things connects smallest sensors and devices that need to be coordinated on the basis of shared data and a shared understanding of vertical domains and application scenarios. As a second example, the Internet of Services envisions a Web of billions of service providers and consumers that interact to collaboratively create an immense service economy. Managing sensor data, or provisioning and consuming services requires automation, as the size and the complexity of the respective settings cannot be feasibly mastered manually. Semantics enables automation, and consequently it is expected that not long from now data and service providers and consumers worldwide will interact, integrate and coordinate billions of semantic artifacts of various types. No doubt, there is a need for novel technologies to provide scalable storage and access infrastructures that cope with the heterogeneity, dynamics, openness, complexity and decentralization of the (Semantic) Web