Apache Ant vs Buck2

Apache Ant is a Java library and command-line tool that runs processes described in build files as targets and tasks. Its tasks compile, assemble, test, and run Java applications, and can also build C and C++ projects. Additional built-in coverage handles archiving, file operations, execution, remote access, source control, and testing. Ant does not impose coding conventions or directory layouts on Java projects. Developers can extend it with Antlibs containing tasks and types, while optional Antlibs are distributed separately from the core release. For projects needing dependency management alongside build tooling, the project recommends Apache Ivy. Ant 1.10 requires JDK 8 or later; many tasks will not work with only a JRE. The JUnit task requires external libraries that are not bundled. Ant has been used on Linux, macOS, Windows NT descendants, Unix, and other platforms, with development focused on Linux, macOS, Windows, and Unix. Releases from version 1.6.1 onward use the Apache License, Version 2.0. The listed free plan is Apache Ant 1.10.18, distributed as ZIP, TAR.GZ, and TAR.BZ2 packages. Download guidance includes PGP signature and SHA512 verification.

Buck2 is a free build system from Meta for large-scale repositories that combine multiple programming languages. It uses Starlark rules, a dynamic dependency graph, and incremental actions to support extensible builds. Its language table lists prelude rules for C/C++, Erlang, Go, Haskell, Java, Kotlin, OCaml, Python, and Rust, though usability varies by language. Build actions can run remotely through services exposing Bazel's remote execution API; the project lists BuildBarn, BuildBuddy, EngFlow, and NativeLink as compatible with its distributed compilation support. Buck2 supports filesystem watching and can integrate with Meta's optional Eden virtual filesystem. Rules are hermetic by default and missing dependencies are errors, but local-only build steps are not sandboxed. The project describes Buck2 as early-stage and says it has no stable release tag; its latest binary tag changes with repository pushes. It warns that outside users may encounter rough edges, missing features, and missing toolchains. Source and binaries are available under MIT and Apache-2.0 licenses. The project directs users to GitHub for issue reports and offers a community Discord server.