This book constitutes the thoroughly referred postproceeding of the International Provenance and Annotation Workshops, IPAW 2006, held in Chicago, Il, USA in May 2006.

The 26 revised full papers presented together with 2 keynote papers were carefully selected for presentation during two rounds of reviewing and improvement. The paper are organized in topical sections on applications in software development, organ transplantation management, scientific simulation, stream filtering, and e-science; data semantics and semantic Web; workflows; models of provenance, annotations, and processes; and provenance systems.