Apache Wicket

Apache Wicket is a component-based Java web framework where each UI element is a Java object backed by a corresponding HTML fragment. Jonathan Locke created it in 2004; it became an Apache top-level project in 2007. Unlike template-driven frameworks, Wicket keeps UI state on the server — components form a tree that tracks user interactions across requests, making complex stateful interfaces straightforward to build in plain Java.

The current major release is Wicket 10 (Java 17+). Wicket’s model enforces a strict separation of logic (Java) and markup (HTML), with no custom tags or expression languages mixing the two. AJAX support is built in: adding dynamic behaviour to a component requires a single Java method override. The framework handles form processing, validation, and i18n natively. The official guide and the API reference cover the component model in detail. The source code is on GitHub under the Apache 2.0 license.