The Sheffield Development Project arose from the thinking behind the 1971 White Paper "Better Services for the Mentally Handicapped", which was a government effort to provide clear leadership and a long-term strategy for the development of services for people with learning difficulties. The Sheffield Development Project has been a major attempt to implement, test and demonstrate a new pattern of community-based services for people with learning difficulties and their families. The project paper evaluates the Project, its achievements and proposals for the future.