Meeting the needs of mathematically gifted and talented students is a challenge for educators. To support teachers of mathematically gifted and talented students to find appropriate solutions, several innovative projects were conducted in schools using funds provided by the New Brunswick, Canada, Department of Education. This article presents one such initiative: a collaborative project we developed with two middle school teachers to enrich the mathematical experience of their most advanced students. We worked with 40 students from both schools, involving them in creating mathematics problems using multimedia tools for the CAMI (Communauté d'apprentissages multidisciplinaires interactifs) website. We analyzed the richness of the problems created by the participants (Manuel, 2010), as well as students' perceptions of their experiences, collected through semi-structured interviews. Students appreciated the experience, and recommended that the project be continued in following years. Most of the problems created by students were moderately rich, and included multiple steps, but were similar to those used in classrooms. Some students stated that they were more comfortable solving problems than creating new ones, which suggested that they found the task challenging. Our results showed that specific programs for students interested in mathematics could provide positive experiences and challenges. Our research also suggested that problem posing in mathematics classrooms needs to be investigated in more depth.