Rustup
rustup is a toolchain multiplexer. It installs and manages many Rust toolchains and presents them all through a single set of tools installed to ~/.cargo/bin. The rustc and cargo executables installed e.g. in ~/.cargo/bin are proxies that delegate to the real toolchain.
This is similar to Python's pyenv or Node's nvm.
Key commands
rustup help
# Show the help page for a subcommand (like toolchain)
rustup toolchain help
# Open the local documentation in your browser
rustup doc
# Update to a new verion of Rust
rustup update
# Show which toolchain will be used in the current directory
rustup show
# Show which toolchain will be used in the current directory
rustup target list
# Overview of what is installed on your system
rustup toolchain list
# See a list of available and installed components.
rustup component list