What’s the difference between JavaScript, JScript, and ECMA?

When Netscape introduced the scripting language for their browser, they named it Javascript, even though it was not related to Sun's Java at all.

Microsoft always make their own version of things, and Javascript is no exception. The result is JScript, and it’s used also in ASP and .NET

ECMAscript is the standardized version of Javascript by ECMA International in ECMA-262 published specs.