Most people with Down's Syndrome (DS) experience low integration with society. There is a perception that they can achieve less than what they really can. Recent research and new opportunities for their integration in mainstream education and work provided numerous cases where levels of achievement exceeded the (limiting) expectations. Contrary to common belief, there is considerable variety and richness between individuals with DS. However, society tends to simplify their view of people with DS, usually in a way which is detrimental to them and in a way which reduces their chances to achieve their potential as citizens, despite having exactly the same rights than everybody else.POSEIDON aims at developing a technological infrastructure which can foster a growing number of services developed to help people with DS to become more integrated, to support their development as citizens and to enable them to make a greater contribution to society. There is a wide range of issues which can be tackled, we provide our contribution starting with a focus on supporting education, work, leisure and socialization.The infrastructure to be developed will provide a development environment which other organizations can use as a stepping stone to develop more new services for inclusion in the future. An outcome will be a working system with basic services to support inclusion which will illustrate the effectiveness and potential of our proposal. We are conscious that people with DS have their own strengths, preferences and needs so POSEIDON will focus on using their strengths to provide support for their needs whilst allowing each individual to personalize the solution based on their preferences.POSEIDON will be co-designed by final users. It has been user-centred from its inception and will give all main stakeholders ample opportunities to shape the output of the project, which will ensure a final outcome which is of practical usefulness and interest to the intended users.