UMLet is an open-source UML tool with a simple user interface: draw UML diagrams fast, export diagrams to eps, pdf, jpg, svg, and clipboard, share diagrams using Eclipse, and create new, custom UML elements.
Trails is a domain driven development framework in the spirit of Ruby on Rails and Naked Objects.
Exactor is a framework for writing automated acceptance tests of the kind advocated by Extreme Programming. Customers or testers write acceptance tests using a simple plain text format. Programmers write the commands specified by the customer tests and co
XL, an extensible programming language, implements the ideas of Concept Programming.