The Rust Ecosystem

The Rust ecosystem consists of a number of tools, of which the main ones are:

  • rustc: the Rust compiler which turns .rs files into binaries and other intermediate formats.

  • cargo: the Rust dependency manager and build tool. Cargo knows how to download dependencies, usually hosted on, and it will pass them to rustc when building your project. Cargo also comes with a built-in test runner which is used to execute unit tests.

  • rustup: the Rust toolchain installer and updater. This tool is used to install and update rustc and cargo when new versions of Rust are released. In addition, rustup can also download documentation for the standard library. You can have multiple versions of Rust installed at once and rustup will let you switch between them as needed.

Key points:

  • Rust has a rapid release schedule with a new release coming out every six weeks. New releases maintain backwards compatibility with old releases — plus they enable new functionality.

  • There are three release channels: “stable”, “beta”, and “nightly”.

  • New features are being tested on “nightly”, “beta” is what becomes “stable” every six weeks.

  • Dependencies can also be resolved from alternative registries, git, folders, and more.

  • Rust also has editions: the current edition is Rust 2021. Previous editions were Rust 2015 and Rust 2018.

    • The editions are allowed to make backwards incompatible changes to the language.

    • To prevent breaking code, editions are opt-in: you select the edition for your crate via the Cargo.toml file.

    • To avoid splitting the ecosystem, Rust compilers can mix code written for different editions.

    • Mention that it is quite rare to ever use the compiler directly not through cargo (most users never do).

    • It might be worth alluding that Cargo itself is an extremely powerful and comprehensive tool. It is capable of many advanced features including but not limited to:

    • Read more from the official Cargo Book