Bun

Bun brand colours

Extracted from the artwork and ranked by how much of the mark each covers — not from a brand book, so treat them as observed rather than official.

Bun is a JavaScript runtime, package manager, bundler and test runner in one binary, written in Zig and built on JavaScriptCore rather than V8. The pitch is speed at every layer — installs, cold start, HTTP throughput — plus removing the four-tool stack most Node projects assemble. It implements a large share of the Node API surface, ships first-class TypeScript and JSX execution with no build step, and includes a SQLite driver, an S3 client and a Postgres client in the standard library. Compatibility gaps have narrowed but still surface in native modules and less common Node internals. It competes with Node.js, which remains the safe default, and Deno, which took the opposite approach of a deliberately different standard library and permissions model. Runtime support is a field in toolweight's sandbox and hosting comparisons, and Bun's presence there is a reasonable proxy for how current a platform is.