The World Wide Web lacks support for explaining information provenance. When web applications return results, many users do not know what information sources were used, when they were updated, how reliable the source was, what information was looked up versus derived, and if something was derived, how it was derived. In this paper we introduce the Inference Web (IW) that addresses the problems of opaque query answers by providing sharable, combinable, and distributed explanations. The explanations include information concerning where answers came from and how they were deduced (or retrieved). The IW solution includes: an extensible registry containing details on information sources and reasoners, a portable proof specification, and an explanation browser.