JScript (ECMAScript 3) is Microsoft's implementation of the ECMAScript 3 standard, primarily used for scripting in Windows environments. Introduced in the late 1990s, JScript enabled dynamic web content and automation within Internet Explorer and Windows-based applications. While similar to JavaScript, JScript includes additional features and objects specific to the Windows platform. It played a significant role in web development and Windows scripting, but has since become largely obsolete with the rise of more secure and modern scripting languages. In cybersecurity, JScript is notable because attackers have exploited its compatibility with Windows Script Host (WSH) to deliver malware or execute malicious code on vulnerable systems.