Buck vs Mill: What are the differences?

Developers describe Buck as "A build system developed and used by Facebook". Buck encourages the creation of small, reusable modules consisting of code and resources, and supports a variety of languages on many platforms. On the other hand, Mill is detailed as "Simple, modern build tool for Scala and Java". It is your shiny new Java/Scala build tool. It aims for simplicity by re-using concepts you are already familiar with, borrowing ideas from modern tools like Bazel, to let you build your projects in a way that's simple, fast, and predictable.

Buck and Mill can be categorized as "Java Build" tools.

Some of the features offered by Buck are:

• Speed up your Android builds. Buck builds independent artifacts in parallel to take advantage of multiple cores. Further, it reduces incremental build times by keeping track of unchanged modules so that the minimal set of modules is rebuilt.
• Introduce ad-hoc build steps for building artifacts that are not supported out-of-the-box using the standard Ant build scripts for Android.
• Keep the logic for generating build rules in the build system instead of requiring a separate system to generate build files.

On the other hand, Mill provides the following key features:

• Simple
• Fast
• Modern

Buck is an open source tool with 7.37K GitHub stars and 1.1K GitHub forks. Here's a link to Buck's open source repository on GitHub.