Why I built Rustic Playground

I bought the Rust Book in 2018. I didn’t open it for seven years.

A sabbatical earlier this year finally cleared the calendar. I tried Python first and decided it wasn’t for me — my mind is wired for C/C++, and runtime surprises felt like the wrong trade. I wanted something that would push me.

The last time I learned a language and actually enjoyed it was Swift, when Swift 2.0 came out. Apple’s Swift book was excellent, but what made it stick was Swift Playgrounds. I could follow along, try things, break them, and learn protocols, generics, and closures without leaving the playground. It was the most fun I’d had with a language since picking up K&R in school.

I opened the Rust Book expecting something similar. The concepts are there — traits, generics, and ownership and borrowing — which I think are more interesting than Swift’s ARC. But following along meant constantly shuttling between a terminal for cargo new, an editor for the .rs file, and back to the terminal for cargo run. VS Code with rust-analyzer is fine, but it isn’t a playground. RustRover is a great IDE, but I didn’t want one that hides the toolchain — I wanted to learn the language and the toolchain.

So I started building what I wished existed.

The first version was a CLI: drop a {name}.rs file in src/bin/, run cargo run --bin {name}. Then a UI around it — write code, press ⌘R, see output stream live. Then dependency management, toolchain install and repair, the Rust Book examples baked in, and eventually C/C++, Zig, and Swift.

There’s a second thread I should be honest about. I was getting into agentic development with Claude Code around the same time, and Rustic Playground became how I learned what that actually looks like in practice. One thing I didn’t expect: Rust’s compiler makes AI-assisted development meaningfully better. The same strictness that makes Rust hard to learn catches a class of bugs before they ever run. If you’re exploring agentic dev, try it on a Rust project.

What pushed this from side project to something I wanted to finish was watching two kids I’d been mentoring try to learn Rust. One is a CS major. They were following instructions without understanding what was happening underneath, getting frustrated, drifting toward giving up. Swift Playgrounds solved that for Swift. Rust deserved something similar.

Rustic Playground is that attempt. It’s macOS-only on purpose, free, and open source.

If you’re learning Rust on a Mac, I’d love for you to try it. Download at rusticplayground.dev, star it on GitHub, and come hang out in the Discord.

— Jagmeet