ECMAScript 5 compatibility table

[1] Results are only applicable for the KHTML rendering engine.

[2] Flagged features have to be enabled via --harmony flag

[3] Flagged features have to be enabled via --harmony or --es_staging flag

[4] Executed in Node.js/JVM mode via graalvm/bin/node --jvm.

[5] Executed using js --js.intl-402.

[6] In Internet Explorer 8 Object.defineProperty only accepts DOM objects (MSDN reference).

[7] In Internet Explorer 8 Object.getOwnPropertyDescriptor only accepts DOM objects (MSDN reference).

[8] Internet Explorer 6 - 8 do not differentiate between a dense array with undefined values, and a sparse array. Specifically, `0 in [,]` and `0 in [undefined]` both yield false - whereas in a compliant browser, the former would give `false`, the latter `true`. As such, ES5 array iteration methods can only be shimmed reliably when dealing with dense arrays.

[9] Hermes isn't supporting strict mode in eval, test result is unrepresentative. See this comment for details

[10] IE10 PP2 fails this test.

[11] Hermes isn't supporting lexical scope in eval, test result is unrepresentative