Gerrit at Eclipse Foundation have really long history. Initially only EGit and JGit projects could use this tool, but starting from February 2012 Gerrit become fist class citizen in Eclipse ecosystem. Every Eclipse Foundation's project can immediately start using its powerful code review capabilities. Capabilities that together with TDD and CI create safety net against bugs for software development.
For quite long time Gerrit features set was pretty closed and adding new functionality required upstream code base changes. That means either you ended up in port and rebase nightmare or contributed your changes back to community... where they could not have been accepted because they solve your domain's problem not something that is vital for the community edition.
Plugin support in Gerrit was initially introduced in version 2.5. Since then amount of available extension points substantially increased. In this presentation we will understand Gerrit plugins architecture. We will discuss extensions and plugins especially differences between them and which one to choose when. We will see how to combine everything together (including WEB UI) to get your first full blown Gerrit plugin.