The Platform SDK contains a business user tool for workflow development called the Guide Designer. The guide designer has a simple interface for creating steps such as screens and automated actions and they can use and modify data in a host system. The guides that you create are applications that run from within a web browser connecting to either an internal or external server. The browser can be within a PC or a computer created by Apple.
The Host Provider SDK and associated Service Programming Interface (SPI) allow developers to expose data and operations in their host system to the Designer. At the heart of the system are reusable services that are defined using the powerful Process Developer environment and deployed to the Process Server environment. These services implement the SPI necessary for providing a hosting environment (Host Provider) and are described to the Process Servr using a simple descriptor mechanism