cross-rs/cross is a CLI tool that enables zero-setup cross-compilation for Rust projects by wrapping Cargo and executing builds inside container engines (Docker/Podman). It manages a comprehensive registry of pre-built Docker images for dozens of target triples (Linux, musl, Android, FreeBSD, NetBSD, Solaris, Windows, bare-metal, etc.), automatically selects the appropriate image based on the --target flag, mounts the project source and toolchain, and runs cargo build/test inside the container. The tool also supports remote Docker execution, custom Dockerfiles, and advanced configuration via Cross.toml and environment variables. The codebase is structured as a Rust CLI with two binaries (cross and cross-util), a library of container orchestration modules, and a developer xtask workspace for CI, codegen, and changelog management. It demonstrates strong engineering practices with extensive CI, testing, and reusable patterns for command execution, container abstraction, and configuration merging. The repository includes a large collection of Dockerfiles and shell scripts for building target-specific toolchain images, as well as CI workflows that test across many platforms and container engines.