This question comes up a lot, and we&#x27;ve debated it a fair bit.<p>There are a few key arguments for keeping them separate from my perspective:<p>First, they have distinct audiences. Cargo is a tool for building Rust programs no matter how you obtained the compiler. rustup is a tool fundamentally for installing the official Rust binaries. So if Cargo contained rustup, that would be a large chunk of features that have an very unclear role when Cargo is distributed by Linux distributions, and would probably need to simply be compiled out.<p>That last point about compiling out rustup also points to the fact that Cargo&#x27;s and rustup&#x27;s features are completely orthogonal. There&#x27;s no <i>technical</i> reason to combine them.<p>Of course, the practical reason to combine them is that one tool is conceptually simpler than two. Even I have found myself accidentally typing `cargo update nightly`, `rustup build`, etc.<p>Finally, releases of Cargo today are paired with releases of rustc. Distributing the Rust installer with Cargo would necessarily change that relationship. That is, there would be one global Cargo that is used with every revision of rustc. This isn&#x27;t necessarily a bad way to arrange the tools, but it is a big change from today that would require significant effort to move to.