What JavaScript engine does Bun use?
Bun uses Safari's JavaScriptCore as its JavaScript engine. This choice sets it apart from Node.js and Deno, which run on the V8 engine used by the Chromium project.
Questions about Bun (software)
Short answers, pulled from the story.
When was the first stable release of Bun 1.0 launched?
The first stable release of Bun 1.0 arrived on the 8th of September 2023. That launch marked the transition from experimental builds to a production-ready tool.
Who announced that Bun would join Anthropic?
On the 2nd of December 2025, Jarred Sumner announced that Bun would join Anthropic via a blog post. The acquisition allows Anthropic to use Bun to support Claude Code and the Claude Agent SDK.
How much funding did Oven raise for Bun in August 2022?
On the 24th of August 2022, Oven announced it had raised $7 million in funding. Kleiner Perkins led this investment round with participation from industry figures including Guillermo Rauch.
Does Bun require separate packages for basic functions like file editing or HTTP servers?
Common tools like file editing, HTTP servers, WebSocket handling, and hashing come bundled within the installation. Developers no longer need to install separate packages for these basic functions.