You could almost hear the collective gasp from the Zig community when Bun announced it was shifting its runtime codebase away from Zig and toward Rust. Suddenly, their flagship success story was being yanked out from under them. The emergence of Cruller—a project continuing Bun’s Zig runtime on Zig 0.16—felt like a heroic rescue mission. But it’s not a victory. It’s desperation.
Let’s be precise about what Cruller actually is: it is not a continuation of Bun. It is a surgical extraction, a subset of the old codebase stripped out for deployment purposes. Everything that made Bun what it is—the features that made it a powerful, all-in-one runtime—has been intentionally removed. As one commenter bluntly put it, “What makes Bun Bun is all the things that got removed from this project.”
When a project is forked not out of a bold new vision, but out of the fear of being forgotten, it isn’t a rebirth—it’s an expensive autopsy.
Why would anyone go through the heroic effort of sifting through an abandoned, transitioning codebase? One developer pointed out that starting a new project from scratch would frankly make more sense. But the creator of Cruller didn’t do that for one simple reason: brand recognition. The name “Bun” carries massive weight. Cruller isn’t surviving on its technical merits; it’s surviving on the life support of Bun’s social capital.
This is the dirtiest open secret in software development. You can fork code, but you can’t fork a community. You can copy a repository, but the driving force, the momentum, and the core maintainers have packed their bags and moved to Rust. Cruller is an attempt to squeeze residual relevance out of a house that’s already been vacated.
In the open-source world, social capital is the only hard currency harder to fork than a codebase.
Forks born from community ruptures have a notoriously high mortality rate. They start with a burst of anger or nostalgia, but once the initial venting subsides, there’s no one left to do the grueling maintenance work. Cruller will only survive if it can leverage the “Bun” name to pull entirely new developers into its orbit—people who don’t care about the original Zig-versus-Rust drama. But why would anyone choose a stripped-down branch over the already powerful and well-maintained Node, or the real, evolving Bun?
I feel for Zig. It hurts to watch a high-profile project walk away. Seeing Ghostty thrive is great, but the sting of losing Bun is real. Yet, clinging to the ghost of a hollowed-out runtime is not the way forward. Zig’s relevance won’t be saved by performing CPR on a project being rebuilt in Rust. It will be saved by proving Zig can stand on its own two feet and build the next great thing.
You cannot fork a project’s soul. Once the community decides to move forward, the only thing left behind is the code, and code rots.
FAQ
Q: Isn't Cruller just a lighter version of Bun that Zig developers need?
A: No. Cruller is a subset extracted for deployment purposes, not a fully-featured runtime. Everything that made Bun powerful has been removed. You are better off using Node.
Q: What's the practical impact if Cruller keeps the Zig runtime alive?
A: It delays the inevitable and traps Zig talent in maintaining a legacy fork instead of innovating on native Zig projects. It's a distraction, not an ecosystem builder.
Q: Doesn't the very existence of Cruller prove Zig is still viable enough to fork?
A: It proves the power of the 'Bun' brand name, not Zig. People are forking it for the clout and recognition, not because they believe a stripped-down Zig runtime is superior to the evolving Rust version.