Multi-project builds are very common in software projects. Gradle has great support for multi-project builds. We can use a hierarchical layout as project structure, but we can easily customize this and use other layouts.

Configuring projects is easy and can be done in one place, at the root of the projects. We can also add project configurations at the project level itself. Not only can we define dependencies between projects on a project library level, but we can also do so via configuration or task dependencies. Gradle will resolve the correct way to build the complete project, so we don't have to worry too much about that.

Because Gradle knows which projects will be involved before a task is executed, we can do partial multi-project builds. Gradle will automatically build project dependencies, which are necessary for our current project. And we can use a single task to build the projects that depend on our current project.

Finally, we saw how we can run our web application code in a Jetty web container, with the Jetty plugin. We apply the plugin and execute the jettyRun or jettyRunWar tasks to run our code as a web application. We can open a web browser and execute our code.

In the next chapter, we will look at how we can use other languages besides Java, with Gradle.