The hack/ directory holds information and tools for everyone involved in the process of creating and distributing Docker, specifically:
If you're a contributor or aspiring contributor, you should read CONTRIBUTORS.md.
If you're a maintainer or aspiring maintainer, you should read MAINTAINERS.md.
If you're a packager or aspiring packager, you should read PACKAGERS.md.
If you're a maintainer in charge of a release, you should read RELEASE-CHECKLIST.md.
A high-level roadmap is available at ROADMAP.md.
make.sh is the primary build tool for docker. It is used for compiling the official binary, running the test suite, and pushing releases.