This article reviews the literature on the role that children can play in the design of information technology applications intended for young users themselves. It discusses several relevant design theories -User-Centered Design, Contextual Inquiry, Participatory Design, Cooperative Inquiry, Informant Design and Learner-Centered Design -looks at usability issues in relation to design and children, and presents a number of studies in which children have been actively involved in the design both of software and web portals. Designers are finding that children as well as adults can have a valuable and complementary role to play in the design process, although its precise nature is a matter of debate.