Increasing amounts of data are shared, often publicly on the World Wide Web, for reuse by third parties. Such reuse usually necessitates the integration of this data with other data, or with software, in order to enable data-based applications, fine-grained search, data analytics, etc. This integration is often a significant cost factor due to the wide variance regarding representational choices for data, ranging from syntactic data formats to semantic heterogeneity stemming from different viewpoints of data providers. In this presentation, we will shed light on the role of knowledge modeling for data sharing and reuse. In particular, we will discuss how Semantic Web Technologies make it easier to integrate and thus reuse heterogeneous data.