http://learningapps.org/index.php?overview&s=&category=0&tool=

LearningApps.org is a Web 2.0 application, to support learning and teaching processes with small interactive modules. Those modules can be used directly in learning materials, but also for self studying. The aim is to collect reusable building blocks and make them available to everyone. Blocks (called Apps) include no specific framework or a specific learning scenario. The blocks are therefore not suitable as complete lessons or tasks, instead they must be embedded in an appropriate teaching scenario.