Provenance, from the French word provenir, "to come from," means the origin, or the source, of something, or the history of an object's ownership or location. A digital object's provenance (also referred to as its audit trail or lineage) contains information about the process and data used to derive the object. Provenance provides important documentation that's vital to preserving data, determining data quality and authorship, and reproducing and validating results. As increasing volumes of data are shared and modified over the Web, it's crucial to track their provenance for business, scientific, and social networking applications. This special issue provides a snapshot of ongoing work in this area. © 2011 IEEE.