GreenMail is a suite of email servers for testing purposes and sandbox development. It supports SMTP, POP3, and IMAP (including SSL) and can be embedded into any Java application or unit test. The GreenMail Service (SAR) extension runs as a JBoss embedded developer mail server sandbox, manageable via JMX.
OpenEJB is a simple, lightweight Enterprise JavaBeans (EJB) container and server. You can embed OpenEJB in your own applications, or in a Web application server like Tomcat, or run it as a standalone EJB server. It supports EJB 3.0, 2.1, 2.0, and 1.1, and has partial support for EJB 3.1.
Kundo provides a structured, convention based approach for Java builds. Kundo has a pluggable, extensible architecture; it harnesses the power and flexibility of Groovy and Ant to provide a highly configurable Java build framework. Kundo achieves this flexibility with a plug-in architecture that attaches behaviors (provided by Kundo plug-ins) to build lifecycle phases. Kundo consists of a kernel and a set of foundation plug-ins. The kernel is responsible for the orchestration of the multiple collaborators within the build system.