This manual establishes the foundational design principles and interaction standards required to develop consistent, functional software for the Apple Newton platform. Authored by the Apple Computer technical staff, this document serves as the primary reference for engineers and designers tasked with maintaining the specific human interface model of the Newton operating system. It provides the logical framework necessary to ensure that third-party applications integrate seamlessly with the device's unique hardware and software constraints.

Industry professionals and historians of mobile computing identify this text as the definitive technical standard for the Newton platform. It remains a foundational document for understanding the early development of mobile user interfaces and pen-based computing paradigms.