systemjs/systemjs

Health v2 · maintenance only

Adoption not part of the score

13093 stars · 1093 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

SystemJS is a hookable, standards-based ES module loader for browsers. It transpiles production ES module builds into the System.register format so they run in older browsers (down to IE11) with near-native speed, supporting dynamic import, top-level await, import maps, and live bindings.

Use cases

• load ES modules in browsers that don't support them natively
• run Rollup code-splitting builds in legacy browsers
• support dynamic import and top-level await in older browsers
• use import maps with Content Security Policy in legacy environments
• load multiple module formats in the browser at runtime

When to choose

• you must support legacy browsers like IE11 with ES module workflows
• you need a hookable runtime module loader with import maps and module types
• you run micro-frontend or dynamic module loading setups in the browser

When to avoid

• your target browsers all support native ES modules
• you only need a bundler or package manager rather than a runtime loader
• you build for Node.js only

Facets

library · maturity stable

build-tool developer-tools web-development frontend developer-tools browser module-loader es-modules system-register import-maps browser-compatibility code-splitting polyfill javascript nodejs

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markdown · JSON · MCP: product_card(name="systemjs/systemjs")