You might just be being facetious, but in case you aren't, that's not true. The EMCAScript specification was based on JavaScript, not the other way around, and

You might just be being facetious, but in case you aren't, that's not true. The EMCAScript specification was based on JavaScript, not the other way around, and there are EMCAScript implementations that are not compatible with JavaScript (e.g. ActionScript, JScript). That is, JavaScript is one of many implementations of the EMCAScript standard, in and of itself it is not simply EMCAScript.