James Duncan Davidson is a freelance author, software developer, and consultant focusing on Mac OS X, Java, XML, and open source technologies. He is the author of Learning Cocoa with Objective-C (published by O'Reilly & Associates) and is a frequent contributor to the O'Reilly Network online website as well as publisher of his own website, x180 (http://www.x180.net), where he keeps his popular weblog. Duncan was the creator of Apache Tomcat and Apache Ant and was instrumental in their donation to the Apache Software Foundation by Sun Microsystems . While working at Sun, he authored two versions of the Java Servlet API specification as well as the Java API for XML Processing. Duncan regularly presents at conferences all over the world on topics ranging from open source and collaborative development to programming Java more effectively. He didn't graduate with a Computer Science degree, but sees that as a benefit in helping explain how software works. His educational background is in Architecture (the bricks and mortar kind), the essence of which he applies to every software problem that finds him. He currently resides in San Francisco, California.