Best free (preferably FOSS) Rust IDE for MacOS

rust-analyzer is a pretty good LSP, and works in most modern text editors.

My advice? Just pick an editor and stick to it.

VSCode? Sure.

Jetbrains? Good choice.

Hell, Emacs? Why not?

I personally use Neovim, and it just works. No matter what I’m programming in, I’m still at home.

Just pick an editor that works for you. I’d suggest VSCode. Use VSCodium for a true FOSS experience, or Helix for a beginner friendly terminal editor.

If you really just want something Rust-focused, there’s RustRover from Jetbrains, but that’s about it.

helix

Vscode works well on Mac, and it has good Rust support.

Just wanted to point that rust-analyzer is the fantastic language server that powers the language support, and it runs in a lot of editors (VS Code, Emacs, Neovim, ...)

There's not going to be a rust-specific FOSS editor AFAIK (nothing like RustRover from JetBrains). However the Rust extensions are first-class experience on VS Codium, Neovim, Emacs, etc.

More importantly, unlike Java, C#, Kotlin, C++, or Python Rust doesn't benefit all that much from a language-specific IDE. There's no bulky management of a virtual environment, no make files, no maven, etc. Just a human-readable cargo.toml for your packages, an install command, and a build+run command.

There’s no bulky management of a virtual environment, no make files, no maven, etc. Just a human-readable cargo.toml for your packages

In your perspective, what's the difference between a cargo.toml and a requirements.txt, packages.json, pom.xml, etc? Is there any?
- Vanilla cargo.toml files are more akin to a requirements.txt than any of the others, which allow you to do things like set variables or create run scripts. However, vanilla cargo.toml files have some minimal Make functionality so it’s a bit more than just project dependencies. Each of those ecosystems has a slightly different approach to handling build tooling and dependency management. Rust puts the basic build and dependencies in one file with the assumption your system has the right Rust version, which is a lot simpler than others.
- To get to your core point; I agree python without a virtual env, just raw python, is definintely not bulky. I'd argue its much more lightweight than cargo. My comment was because sounds like OP could be new-ish to programming, and, for a number of projects (ex; Android development), going from a big IDE to just a plaintext editor + command line commands can be a really painful jump. I remeber a Java course having a series of IDE tutorials and I could not for the life of me figure out the plaintext+commandline equivlent. The same can happen for certain python projects if a tutorial expects the editor to set the PYTHONPATH and the project has a venv, and the tutorial expects the editor's terminals start already-inside python virtual environment. That kind of stuff can make 'python without an IDE" confusing and daunting to someone merely following PyCharm tutorials.
  
  I just wanted to assure OP they likely wouldn't have that kind of experince with Rust. AFAIK Rust tutorials rarely (if ever) assume an IDE.
  
  Being not-bulky isn't a rust specific thing, a half-decent package manager meets the qualitification, but OP was asking about Rust and might not know.

Not technically IDEs, but you can try Helix or Lapce, both written in rust.

I love Lapce, but it is not what I'd call a Rust IDE. It's a beta/alpha general text editor with some initial extensions for Rust.

Not really a great place to start learning Rust
- I think both of these are just editors written in Rust.

Doom Emacs with lsp and rust-analyzer

VIM + plugins

I have to admit that while I'm old enough to remember VIM from days of yore, I never found the love that everyone had/has for it. Is it really as good as modern IDE's?
- Yes. Though neovim has stolen the limelight really. YCM or ALE with vim, ctrl+p plugins, nerdtree, lightline and you basically have an IDE
- If you're going the vim route I'd go with NeoVim. The lua support for plugins has resulted in some really great IDE-like plugins. That being said, I still prefer VScode with vim mode.
  
  There's actually a cool plugin for VSCode that lets you bridge NeoVim into it if you want the best of both worlds
its always an option.
- VIM is more than an option. It transcends languages, frameworks, paradigms. Vim will always be there for you
Ooorr… vscode with vim extensions/keyboard mappings. :)
- I tried: things like string subs didn't work, no visual block mode, macros non-existant
  
  Real Vim for me!

Definitely VSCode (or one of the many forks).

I also recommend combining it with Docker, the Remote Development extension, and Dev Containers, to keep your dev environment isolated from the rest of your operating system. That way you'll be able to easily install things you're not sure if you want to use, and cleanly rollback/remove them.

It'll also make life easier when (not if) you need to move your dev setup to another computer. Possibly even a completely different operating system.