IDEs – Integrated Development Environments – traditionally provide out of the box support for many of the tasks that go into making working software out of source code. But increasingly, developers expect to be able to use any one of a variety of special-purpose tools for each task. This shifts the focus of the IDE from “Integrated” to “Integrating” external tools into a coherent experience. We have an ever growing number of build tools to compile and build our code into useful artifacts. From my experience integrating sbt and other new tools with the IntelliJ Scala plugin, I have expanded focus to the Build Server Protocol, and will talk about how it enables IntelliJ to interface with even niche build tools in a variety of languages.