Mario Heiderich is a Cologne, Germany-based freelancer and entrepreneur who is devoted to Web application development and security and is currently working on several projects while earning his Ph.D. at Ruhr University in Bochum. He graduated from the University of Applied Sciences in Friedberg/Hessen with a degree in media informatics, and has been working for several German and international companies as a developer and security consultant. In addition to being lead developer for the PHPIDS and author of a German book about Web application security, he has been a speaker at several conferences and a trainer for Web security classes around the world. His work is focused on client-side attacks and defense, especially markup, CSS, and JavaScript, on all major user agents.

Eduardo Alberto Vela Nava (Application Security Specialist—ASS) works as an information security researcher at Google Inc., with the task of improving the security of Google and the Internet as a whole, by researching security problems and creating solutions to them. His primary focus is Web application security and browser/plug-in security. He has been a presenter focusing on Web security at several conferences around the world. He previously worked at Alibaba Cloud Computing and Hi5 Networks.

Gareth Heyes is based in the United Kingdom and does Web security contracting work and the occasional Web development project. He has been a speaker at the Microsoft BlueHat, Confidence Poland, and OWASP conferences, and is the author of many Web-based tools and sandboxes, including Hackvertor, JSReg, CSSReg, and HTMLReg.

David Lindsay is a senior security consultant with Cigital Inc., where he works with industry-leading financial, health care, and software companies helping to secure their critical applications. He provides professional assessments and remediation assistance in the form of penetration tests, architecture risk analysis, code review, and security training. He researches Web application security vulnerabilities focusing on emerging security issues related to new standards, frameworks, and architectures. He has spoken at many leading security events over the past few years, including the Microsoft BlueHat, BlackHat, and OWASP conferences.

He graduated from the University of Utah in 2005 with a master's degree in mathematics. He resides in Ashburn, Virginia, with his wife, Tina, and daughter, Lydia.