What is ECMAScript, ECMA-262, and JavaScript?

ECMAScript is the standardized scripting-language procedures and specifications by the (European Computer Manufacturers Association) ECMA International. The best-known implementation of these scripting-language standards and procedures is JavaScript, JScript, and ActionScript.

JavaScript is the scripting language, which was created within ten days, developed by Brendan Eich for Netscape. It was originally named Mocha, then renamed LiveScript and finally to JavaScript. The prefix Java makes it seem like it has some type of relation to Java the interpreted programming language, but it does not. JavaScript and Java are two different languages.[1]

JScript is Microsoft’s implementation of ECMAScript but could be described more efficiently as a dialect of ECMAScript.[2]

ActionScript is another dialect of ECMAScript that was originally developed by Macromedia Inc. for Macromedia Flash before it got acquired by Adobe and became Adobe Flash; later changed to be known as Adobe Animate.[3]

One of the most popular supersets of JavaScript would be Microsoft own open-source language TypeScript. Typescript transcompiles to JavaScript. What that means is that it takes its current source code and produces the source code in a different language like in this instance JavaScript. Why use it then? Well, as its name states, it has static typing as well as other features. Typescript has a more object-oriented programming approach compared to JavaScript.

There’s always confusion between ECMAScript, JavaScript, and the technical standard language specification ECMA-262. This snippet from an interview with InfoWorld and Brendan Eich should give some insight to it:

InfoWorld: What’s the difference between ECMAScript and JavaScript, or are they one and the same?
Eich: ECMAScript is the standards name for the language. Its number is ECMA-262 and it’s a name that the standards body came up with because they couldn’t get anybody to donate a trademark that was agreeable to all parties. So there’s an issue with marketing the programming languages.
JavaScript would have been the ideal name because that’s what everyone called it and that’s what the books call it. Microsoft couldn’t get a license from Sun so they called their implementation JScript. So ECMA wanted to call it something and they couldn’t get anybody to donate or they couldn’t get everybody to agree to a donation of the trademark, so they ended up inventing ECMAScript, which sounds a little like a skin disease. Nobody really wants it.
And so you have this funny [situation] where you have a standard with a funny name or number and then various implementations that have trade names. And the trade names don’t have a huge value, except JavaScript is the common name. It’s in all the books, it’s what people say. [4]

References

1 D. Crockford, "JavaScript: The World's Most Misunderstood Programming Language," 2001. [Online].

2 "JScript (ECMAScript3)," 23 October 2011. [Online].

3 "Where is Flash Professional?," 8 May 2019. [Online].

4 P. Krill, "JavaScript creator ponders past, future," InfoWorld, 23 June 2008. [Online].