Cruller: A Lightweight Bun Runtime Ported to Zig 0.16 for Production
Cruller: Bun's Zig Runtime, Continued on Zig 0.16
I created Cruller by stripping Bun down to its core runtime components and porting it to vanilla Zig 0.16. This project removes development tools like the package manager and bundler to focus solely on running pre-built JavaScript servers efficiently. The result is a significantly smaller binary that maintains performance parity with the official Bun release while offering a clean path for embedding the engine into other Zig applications.
I initially thought the move to Rust was just a marketing stunt by Claude to show off how powerful their AI is.
- Skywalker13
I don't understand why the git history has been pruned in this fork.
According to the first commit in this fork:
> Squashed as a single orphan commit — the original oven-sh/bun history
isn't relevant to this stripped fork and its shallow clone doesn't
push cleanly to a fresh remote.
IMHO it's always a bad decision to do that. Here, all commit authors are lost. The original history is always relevant.
- andai
There seems to be some confusion here (including in the linked discussion?) about what this is. This is not continuing the development on the original Bun (Zig) codebase.
It is extracting a subset of that codebase for deployment purposes. The full version of Bun (presumably in Rust?) will continue to be used for actual development.
So it is not a replacement for Bun, but a supplement to it.
- dbalatero
> My idea is to strip the system down as much as possible and leave only what is required for production.
> Development would be done using the full Bun runtime, while production would use its lightweight fork, Cruller. I do not have the resources of the Oven team to develop and maintain a massive general-purpose runtime, so I want to focus on specific production requirements.
I don't know about others, but I don't think I would deviate my development runtime from my production runtime so significantly. The chance for behavior that only rears its head in production is too high for my liking.
- pjmlp
As usual, most forks created out of community rupture eventually die.
- ksec
This got me thinking, What if you feed Bun's code into AI, and instead of Rewriting it in Rust, tell it to follow TigerStyle as much as possible?
- holysantamaria
What makes Bun Bun is all the things that got removed from this project. Node is already powerful enough and well maintained. Why would anyone use this?
- theawesomekhan
One thing to point out is all the author's comments seem LLM generated and so does the README and the latest commit to the branch (large explanation in a comment and then change)..
- bradhe
Nice this is going to be a fun project to watch for 2 weeks before everyone forgets about it!