The CDE desktop is quite different from the OpenWindows desktop, although it contains many of the same types of tools. The most obvious difference is that it is a Motif desktop. Read the "Architectural Overview" chapter of Common Desktop Environment: Programmer's Overview for a discussion of the end user and development environment architectural structure. Also read about:
Motif: See "Motif 2.1 Documentation" and "Motif Programming" for a listing of Motif documentation.
CDE Look and Feel: Refer to Common Desktop Environment: Style Guide and Certification Checklist for details. To be style-guide compliant, your application must pass the checklist at the end of the book.
CDE runtime and Development Environments: See "CDE Documentation" for a listing of all CDE documentation that Sun provides. In addition, the desktop applications each have online help volumes.