It was designed for building small, reusable modules consisting of code and resources within a monorepo.

[5] It supports many programming languages, including C++, Swift, Unix Shell, Java, Kotlin, Python, Lua, OCaml, Rust and Go.

It can produce binary outputs for a variety of target platforms including iOS, Android, .NET, and Java virtual machine (VM) runtime systems.

Because all dependencies are explicit and Buck has a directed acyclic graph of all source files and build targets, Buck can perform incremental recompilation, only rebuilding targets downstream of files that have changed.

One of the key features was the ability to share build results between multiple developers and continuous integration (CI), as Buck1 supports a HTTP Cache API.