Equinox is an Eclipse project that provides a certified implementation of the OSGi R4.x core framework specification. It is a module runtime that allows developers to implement an application as a set of "bundles" using the common services and infrastructure.
Equinox began as a project to replace the original Eclipse plug-in runtime in version 3.0 of Eclipse (circa 2004). The open source project was seeded with code donated by IBM's Service Management Framework (SMF) product team[clarify]. It was further developed to meet the needs of the Eclipse community. The adaptations were made into the OSGi specification process, with many being incorporated in the R4 release of the OSGi framework specification. Since then, Equinox has been the reference implementation for the OSGi framework specification.