We try to keep the Qi4j Core Runtime as lean as possible, and a lot of the power to the Qi4j Platform comes via its Extension SPI, which defines clear ways to extend the platform. There are currently the following Extensions types, each with possibly more than one implementation;
This section will go through each of the available extensions. The Qi4j Extensions are of varying maturity level and we try to maintain a STATUS (dev-status.xml) file indicating how good the codebase, documentation and unit tests are for each of the libraries. This is highly subjective and potentially different individuals will judge this differently, but at least it gives a ballpark idea of the situation for our users.