Preprint of paper published in: OOPSLA 2008 - ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications, 19-23 October 2008; doi:10.1145/1449814.1449858 WebDSL is a domain-specific language for the implementation of dynamic web applications with a rich data model. It consists of a core language with constructs to define entities, pages and business logic. Higher-level abstractions, modeling access control and workflow, are defined in a modular fashion as extensions of the core language.