WMLScript

WMLScript is a scripting language used to add client-side logic to WML (Wireless Markup Language) documents within the Wireless Application Protocol (WAP) ecosystem. It originated in the late 1990s as part of the WAP specification and was designed for early mobile devices with limited processing power and memory. WMLScript is a JavaScript-like language that is smaller and simpler than standard JavaScript, intended to run on device-based WMLScript engines.

WMLScript code is embedded in WML cards and can be executed on the client side to provide interactivity, form validation, and basic data processing. It can respond to user events such as card transitions and form submissions, and it can interact with server-side components through WAP mechanisms like fetch operations and data submission. Depending on the implementation, WMLScript can be executed by interpreting the script or by running precompiled bytecode.

The language was standardized by the WAP Forum, which later became part of the Open Mobile Alliance, as part of the WAP 1.x specifications. In practice, WMLScript offered a subset of JavaScript features tailored to the constraints of early mobile devices, but it never achieved the broad ubiquity of JavaScript on standard web pages. Its usage declined as mobile browsing shifted toward XHTML/HTML-based content and modern JavaScript, leading to the eventual retirement of WAP and WMLScript in favor of more capable web technologies.