Seaside is not template-oriented, and does not offer generating or using HTML templates; HTML markup is generated programmatically. (The Seaside-based Pier content-management framework does offer wiki-markup syntax for templating.) Seaside uses callbacks on closures to specify actions to be taken when clicking on a link or submitting a form. The developers and users of Seaside argue that this helps enforce separation of structure (markup) from content and presentation (Cascading Style Sheets (CSS)). Seaside's combination of components, callbacks, and closures can significantly reduce the semantic gap between a complex workflow and its representation in code.