A database for various polyfills that includes:

• Which browsers support a feature
• Associated modules or files for each feature

Types of polyfills:

• polyfills - runtime JS polyfills for polyfills
• recast - JS transpilation using recast and ecstacy
• postcss - CSS transpilation using postcss and ecstacy

Of course, we want to actually test each bundle on a browser. Right now, tests are in paas, so everytime you add a polyfill, checkout paas and see if hitting GET /test.html works in all your browsers. CI testing is coming!

Most updates are currently done manually. Please help add polyfills and update the relevant versions. Some helpful resources are:

• HTML5 Cross Browser Polyfills
• caniuse
• MDN
• ES Compatibility Table
• esnext and its organization
• cssnext and the postcss organization

regenerator includes es7-async-fn. If you use regenerator, be sure to not use es7-async-fn, or at least the runtime.