FUnit is the first generation xUnit testing tool to leverage the custom metadata capabilities of the Flex mxmlc compiler. The tag-based attribute model of FUnit makes it the most intuitive unit-testing framework ever created for the Flex platform.
RCPUnit is an unit testing framework, an automatic GUI testing framework, and a plugin for Eclipse RCP. It runs with PDE JUnit or other unit testing frameworks. It brings you the ability to do unit testing easily in RCP applications, and SWT application.