XML is a critical ingredient in peer-to-peer information sharing schemes, including grid computing, instant messaging, and Web services. In this article, the author explores the cutting-edge efforts intended to create a unified P2P fabric based on adaptations of existing XML technology. P2P platforms seek to share data and link applications that might otherwise be incompatible. The engine fueling P2P communications is driven by XML communications. Virtually all emerging P2P platforms rely on XML to make data digestible And XML communications and protocols are built into a number of proposed standards that are rapidly gaining acceptance in the P2P development community