Seaside: A flexible environment for building dynamic web applications. Page-centric Web development structures an application into individual scripts, each responsible for processing a user request and generating a response. Although software developers have long considered go-to statements harmful, they are still present in today’s mainstream frameworks, and they hamper the reuse of pages in different parts of the application. In this article, after briefly discussing the key challenges of modern Web application development, we present Seaside, a highly dynamic framework for developing Web applications in Smalltalk. The Seaside framework provides a uniform, pure object-oriented view for Web applications. Exploiting Smalltalk’s reflective features, Seaside reintroduces procedure call abstraction in a client-server context. Furthermore, there’s no need to recompile and restart Seaside application servers after each modification. Web developers debug and update applications on the fly, thus reducing development time considerably.