JavaScript is a computer language that Brendan Eich, a developer at Netscape Communications Corporation, initially introduced in the middle of the 1990s. The demand for a scripting language that could be integrated into websites to improve their usefulness and interaction led to the development of JavaScript.

Originally known as Mocha, LiveScript, and then finally JavaScript, Netscape decided to change its name to better reflect the popularity of Java, another well-liked programming language at the time. Despite its name, JavaScript only shares a few superficial syntax similarities with Java.

Microsoft introduced JScript, a version of JavaScript that was backwards compatible with Netscape’s JavaScript, in 1996. The two implementations did, however, differ slightly, which led to compatibility concerns and made it challenging for programmers to design code that consistently functioned across various browsers.

To solve this issue, Netscape asked the European Computer Manufacturers Association (ECMA) to develop a standard specification for JavaScript in 1997. In order to guarantee uniform behavior across all platforms, the resulting standard, known as ECMAScript, offered a set of rules and principles for implementing JavaScript that all browser vendors could follow.

Since then, the ECMAScript definition has undergone numerous revisions, adding new features and functionalities with each iteration. ECMAScript 3 (1999), ECMAScript 5 (2009), ECMAScript 6 (2015), ECMAScript 2016, and ECMAScript 2017 are the versions that have undergone the most substantial revisions.

JavaScript is one of the most widely used programming languages in use today, and it is frequently used to create mobile, server-side, and web apps. Its ease of use, adaptability, and the abundance of frameworks and libraries available for it, including React, Angular, Vue.js, and Node.js, are the reasons for its popularity.