Mark ONeill is the principal author of Web Services Security (McGraw-Hill/Osborne, 2003). Mark has written on the topic of XML and web services security in magazines such as Web Services Journal, XML Journal, Java Pro, Enterprise Architect, Infoconomy, and Technology for Finance. As Chief Technical Officer at Vordel, a pioneering vendor of XML security products, Mark has met many early adopters of XML, gathering and synthesizing their security requirements. Mark regularly presents training courses on web services security in London, California, and on the U.S. East Coast. For the past four years, he has been chosen as a speaker on the topic of XML security at the RSA Conference, the infosec industrys largest annual conference. Mark lives in an old house in Bostons up-and-coming Roslindale neighborhood, with Kristen and their two-year-old son Ben.