1. flat & flatMap array methods

    Methods to flatten any sub-arrays found in an array by concatenating their elements.

  2. Brotli Accept-Encoding/Content-Encoding

    More effective lossless compression algorithm than gzip and deflate.

  3. CSS text-size-adjust

    On mobile devices, the text-size-adjust CSS property allows Web authors to control if and how the text-inflating algorithm is applied to the textual content of the element it is applied to.

  4. compressionstream api: `compressionstream()` constructor: "deflate" compression

  5. compressionstream api: `compressionstream()` constructor: "deflate-raw" compression

  6. decompressionstream api: `decompressionstream()` constructor: "deflate" compression

  7. decompressionstream api: `decompressionstream()` constructor: "deflate-raw" compression

  8. javascript built-in: array: flat

  9. javascript built-in: array: flatmap

  10. javascript built-in: iterator: flatmap

  11. ecmascript 2019 (es10)