Rational Application Developer is an integrated development environment that helps Java software developers design, develop, and deploy their applications. It contains specialized wizards, editors, and validators for a variety of technologies:
Java Platform, Enterprise Edition (Java EE): This architecture is used to build distributed Web and enterprise applications. Java EE applications include: Enterprise Java beans (EJB) applications for distributed, secure applications with transactional support, Java Persistence API (JPA) applications to access persistent data, and JavaServer Pages (JSP) or JavaServer Faces (JSF) for developing presentation logic.
Web services: A Web service is a self-contained, self-describing, modular application that can be published, located, and invoked across the Internet. Web services tools enable software developers to discover existing Web services for integration, create Web services from existing artifacts or from Web Services Description Language (WSDL) files, and to deploy Web services to a variety of environments.