Needle-Extras is an add-on library to Needle, providing additional services and functionality beyond what the core Needle system provides. . This is a kind of testbed of new services and techniques. If a service in Needle-Extras is found to be particularly valuable, it may be promoted into the core Needle framework. . Currently this includes a form of interface injection (thanks to Christian Neukirchen), a simplified means of depending on third-party services, and a general multicasting service.