This document provides an overview and evaluation of various application platform as a service (APaaS) vendors. It describes the APaaS market and features, and evaluates vendors like Mendix, OutSystems, Progress Pacific, Force.com, and SAP ByDesign based on criteria like architecture, skills required, pricing models, and vendor vision. Representative vendors are scored and key differences between vendor offerings are highlighted. The document aims to provide guidance for selecting an APaaS vendor.