This chapter has two purposes. The first is to show a number of interesting plugins. The second is to briefly review how plugins work. If you are not a programmer, then feel free to skip the how plugins work discussion.
When I started writing this book, there were over 300 Jenkins plugins available; at the time of writing this page, there are more than 400. It is likely that there are plugins already available that meet or nearly meet your needs. Jenkins is not only a Continuous Integration Server but also a platform to create extra functionality. Once a few concepts are learned, a programmer can adapt the available plugins to his/her organization's needs.
If you see a feature that is missing, it is normally easier to adapt an existing one than to write from scratch. If you are thinking of adapting, then the plugin tutorial (https://wiki.jenkins-ci.org/display/JENKINS/Plugin+tutorial) is a good starting point. The tutorial gives relevant background information on the infrastructure...