Silverpeas Kernel is the technical foundation upon which are built all the code of the Silverpeas projects. It provides common objects, technical APIs, and wrappers of libraries or frameworks about technical need like, for example, logging or IoC/IoD (Inversion of Control/Injection of Dependency).

The goal of wrappers is to provide to the Silverpeas projects an API for usual tools and that are agnostic to any solution providers so that the change of an implementation can easily transparently be done without having to modify the code of the Silverpeas projects. Because Silverpeas Kernel must be itself agnostic to any frameworks, its code must be built only upon the Java standard library. This is why the implementation of the wrappers are loaded by the Java Service Provider Interface (SPI).

The more important technical components provided by Silverpeas Kernel are:

• An API to access the resources of the Silverpeas projects (l10n bundles, configuration properties, ...)
• A wrapper for logging. By default if no candidate is available by SPI, it is the Java Logging system that is used.
• A wrapper for IoC/IoD (Inversion of Control/Injection of Dependency). The wrappers is based upon the JSR-330 and as such it expects the implementation to be compliant to this specification.

Beside the code, Silverpeas Kernel provides also a library to write unit tests based upon the APIs and the wrappers provided by its technical library. For doing, it provides a simple implementation of some of the wrappers as well as some Junit extensions to ease the access of resources in the tests.