SpringSource Application Platform is a completely module-based Java application server that is designed to run enterprise Java applications and Spring-powered applications with a new degree of flexibility and reliability. The SpringSource Application Platform is based on the new SpringSource Dynamic Module Kernel™ (dm-Kernel). The dm-Kernel provides a module-based backbone for the server, which also harnesses the power of Spring, Apache Tomcat and OSGi-based technologies
Felix is a community effort to implement the OSGi R4 Service Platform, which includes the OSGi framework and standard services, as well as providing and supporting other interesting OSGi-related technologies. The ultimate goal is to provide a completely compliant implementation of the OSGi framework and standard services and to support a community around this technology. Felix currently implements a large portion of the OSGi release 4 specification, but additional work is necessary for full compliance. Despite this fact, the OSGi framework functionality provided by Felix is very stable.