Vikram Vaswani is the founder and CEO of Melonfire (http://www.melonfire.com), a company specializing in software consultancy, and content creation and syndication services.

Vikram is also the author of numerous well-received articles on open-source technologies (including Perl, Python, XML, and the very popular PHP 101 series), all written with the goal of making complex technologies accessible and understandable to novice users. He has been developing software since 1995, was first introduced to PHP in 1998, and hasn't looked back since. His favorite activities include reading, sleeping, watching movies, playing squash, and fiddling with his PalmPilot.

These reviewers contributed their considerable hands-on expertise to the entire development process for XML and PHP. As the book was being written, these dedicated professionals reviewed all the material for technical content, organization, and flow. Their feedback was critical to ensure that XML and PHP fits our readers' need for the highest-quality technical information.

Zak Greant is lead developer for 51 Degrees North, and is the founder of the Foo & Associates programmer's cooperative. He leads the PHP Quality Assurance Team, and is an active contributor to the PHP documentation, mailing lists, and source code. (See http://www.zend.com/comm_person.php?id=56 for his PHP community profile.)

Mark Nenadov is a bright, young software developer living in Canada (he does not reside in an igloo or speak French, however). Mark specializes in Open Source technology, and has lots of experience with technologies such as PHP, XML, MySQL, and Python. He is currently employed at a growing e-commerce company in Windsor, Ontario. When he isn't hunched over his keyboard, he is usually trying to learn new things, playing ice hockey, writing, reading books, and wishing it were a bit warmer in Canada.