JSPM vs Rush

JSPM is an open-source project for managing browser dependencies through import maps. Its CLI is the main package-management tool for import maps, while the jspm.io CDN loads optimized npm dependencies directly, without a separate build step. The development server can install packages automatically, hot-reload, and strip TypeScript types. For production, jspm build uses RollupJS to bundle package entry points and dependencies. JSPM supports native ES modules and standards-based browser workflows, and can add Subresource Integrity hashes across an application's static and dynamic module graph. Built-in providers include jspm.io, nodemodules, esm.sh, unpkg, skypack, and jsdelivr; custom providers can also be configured. Integrations include an online generator, VSCode web extension, Vite plugin, experimental Node.js loader, Import Map Rails, and Symfony AssetMapper. The hosted API generates import maps and dependency graphs, though JSPM recommends running its Generator library directly when possible. Import maps are supported in recent Firefox, Safari, and Chrome, and in Deno. The project costs nothing; CDN services are described as free and donation-supported. Its publish command is experimental and has no reliability guarantees for publishing on jspm.io.

Rush is a monorepo manager for JavaScript developers who build and publish many packages from a shared Git repository. It can install dependencies, link projects, build, generate change logs, update versions, and publish packages to an npm registry. Build modes include parallel, subset, incremental, and distributed builds. Rush puts dependencies in a common folder and uses symlinks to recreate a node_modules folder for each project. Its installation algorithm supports PNPM, NPM, and Yarn. For releases, it gathers change files and updates package versions and changelogs before publishing. Project folders remain self-contained: they can be built without Rush or moved to a separate repository without code changes. Rush runs on Linux, macOS, and Windows; its getting-started demo lists NodeJS as the only prerequisite. Plugins can share configuration and extend features, but the plugin framework is marked experimental. Microsoft does not provide official support; community help is directed to GitHub issues and Rush Stack Zulip. Rush is free and open source.