The company Anthropic, which promotes the Claude family of large language models, acquired a startup developing an open JavaScript platform Bun, touted as a high-performance analogue of the Node.js and Deno platforms. The main reason for the acquisition is the desire to ensure the stable development of the Bun platform, which is used in the Claude Code and Claude Agent SDK products. After the deal is completed, the project will remain open and publicly developed on GitHub, will continue to be delivered under the MIT license, will be maintained and developed by the same team and will maintain its priorities (focus on high performance and compatibility with Node.js).
The Bun project is written in Zig and C++, and is being developed with an eye to ensuring compatibility with server-side applications for Node.js and supports most of the Node.js API. The platform includes a set of tools for creating and running applications in JavaScript and TypeScript, as well as a runtime for running JavaScript applications without a browser, a package manager (NPM compatible), tools for running tests, a system for building self-contained packages, and a layer for embedding handlers written in the C language. In terms of performance, Bun is noticeably ahead of Deno and Node.js (in tests based on the React framework, the Bun platform is 2 times faster than Deno and almost 5 times faster than Node.js). To execute JavaScript, the JavaScript engine JavaScriptCore and project components WebKit with additional patches are used.