GujChat is a chat server management system which can manage different chat servers, each one serving different rooms. A single GujChat installation is capable of serving diverse Webmasters with different templates, rooms and configurations. GujChat is completely multi-lingual and can be installed under any Servlet API 2.2 (or newer) compliant servlet container.
Pulga is a program for numerical simulation of dynamical systems. It is designed to provide a way for students and researchers who study dynamical systems to model them on a computer and analyze them numerically without the difficulty of traditional computer programming languages.
VRaptor 2 is a Web-based MVC and IOC framework based on many frameworks and ideas (Seam, Stripes, Webwork, Hibernate Annotations, etc). It makes full use of Java 5 Annotations. It favors convention over configuration, because configuration in XML/properties/annotations is always easy to make mistakes and repetitive (aka copy and paste in many places). This framework uses a more imperative approach, instead of having many XML files to configure lifecycle and other properties. Most of the settings go inside plain Java objects (POJO), so the team knows exactly what is going on and where.