The Java Engine for Testing (JET) is a system for running distributed automated tests. It has been used by Sun for testing the High Availability DataBase (HADB), JavaDB, PostgreSQL, Memcached, and the MySQL Cluster Manager. JET should be a good way to write your tests if the product you want to test is distributed or has a client/server architecture, if it is natural for you to write the tests in Java, and if you want to invest time in developing tests and abstractions for later reuse.
Project Open ESB implements an Enterprise Service Bus (ESB) runtime with sample service engines and binding components. Open ESB allows you to easily integrate enterprise applications and Web services as loosely coupled composite applications. This allows you to seamlessly compose and recompose your composite applications, realizing the benefits of a true Service-Oriented Architecture (SOA). The core of the Open ESB SDK is based on Java Business Integration (JBI) technology, as defined in the JSR 208 specification.