The chapters in this part describe how to construct Ptolemy II models for web-based modeling or building applications. The first chapter includes an overview of Ptolemy II software, and a brief description of each of the models of computation that have been implemented (and some that are just planned). It describes the package structure of the software, and includes as an appendix a brief tutorial on UML notation, which is used throughout this document to explain the structure of the software. The second chapter includes a tutorial on constructing applets. The third chapter gives an overview of domain-polymorphic actor libraries. Model builders will also want to refer to the domain chapter for the particular domain(s) they are using, since domain-specific actors are described there.