Witold Wysota is a software architect and developer living in Poland. He started his adventure with Qt in 2004 when he joined QtForum.org and started answering questions about programming with Qt. Shortly afterwards, he became part of the moderator group of the forum. In 2006, together with the moderator team, he established QtCentre.org, which quickly became the largest community-driven support site devoted to Qt. For a number of years, he conducted commercial, academic, and public trainings and workshops and has been giving lectures on Qt, Qt Quick, and related technologies. He is a certified Qt developer and was a member of Qt Education Advisory Board with Nokia, where he helped prepare materials in order to use Qt in educational activities. Witold was also a technical reviewer for Foundations of Qt Development, Johan Thelin, Apress Publishing, a book about Qt 4, and an author of a couple of articles on programming with Qt. In real life, he is a passionate adept of Seven Star Praying Mantis, a traditional style of Chinese martial arts. Lorenz Haas is a passionate programmer who started his Qt career with Qt 3. Thrilled by Qt's great community, especially the one at QtCentre.org, he immersed himself in this framework, became one of the first certified Qt developers and specialists, and turned his love for Qt into his profession. Lorenz is now working at a medium-sized IT company based in Erlangen, Germany, as a lead software architect. He mainly develops machine controls and their user interfaces as well as general solutions for the industry sector. Additionally, he runs his own small consultancy and programming business called Histomatics (http://www.histomatics.de). A few years ago, he started contributing to Qt Creator. He added a couple of refactoring options that you probably rely on a regular basis if you use Qt Creator. He is also the author of the Beautifier plugin.