Open Source J2EE Frameworks

AppFuse is an open source project/application that uses best-of-breed Java open source tools to help you develop web applications quickly and efficiently. Not only does it provide documentation about developing lightweight POJO-based applications, but it comes out of the box with features that many applications need, including features for authentication and authorization, user management, Remember Me, password hint, signup, SSL switching, e-mail, URL rewriting, skinnability/page decoration/templated-layout and file upload. This out-of-the-box functionality is one of the main features in AppFuse that separates it from the other \"CRUD Generation\" frameworks, including Ruby on Rails, Trails, and Grails.