ncc vs Rslib

ncc is a free, MIT-licensed command-line tool for compiling a Node.js module and its dependencies into one file. It is distributed through npm as `@vercel/ncc`, with `npm i -g @vercel/ncc` given as the global installation command. The project targets publishing minimal npm packages and sending only relevant application code to serverless environments. Its design goals include zero configuration, built-in TypeScript support, and handling Node.js programs and npm modules. Inputs can include TypeScript, binary addons, and dynamic requires. Build options cover minification, source maps, watched builds, external modules, and ECMAScript target selection. Node.js programs can call ncc programmatically with options for caching, externals, minification, source maps, and asset builds. `.ts` and `.tsx` inputs require a `tsconfig.json`. Module-format behavior includes automatic ES module output for `.mjs` files and `.js` files inside a `type: module` package boundary. Support examples cover Sequelize with MariaDB and `@google-cloud/vision` with `google-proto-files`. Dynamically loaded assets that static analysis cannot identify may not work correctly. It runs on Linux.

Rslib is a free, open-source tool for developing JavaScript packages and UI component libraries. Based on Rsbuild and powered by Rspack, it integrates Rust-based tools including SWC and Lightning CSS. It supports bundle and bundleless build modes and outputs ESM, CJS, UMD, Module Federation, and IIFE formats. Framework integrations support component libraries for React, Vue, Svelte, and Solid. Rslib can generate TypeScript declaration files, including isolated declarations, though declaration generation is not enabled by default. Plugin support includes Rsbuild, Rspack, and webpack plugins. Its development integrations include Rstest for testing, Storybook for component development, Rspress for documentation and component previews, and Rsdoctor for build analysis. The quick-start guide lists Node.js, Deno, and Bun as runtime options, while Rslib v1 requires Node.js 20.19+ or 22.12+. It is available for API, Linux, macOS, web, and Windows, and is released under the MIT license.