RequireLX meetup

Although the lingua franca of the Web is JavaScript, the DOM and associated interfaces are actually expressed in a language called WebIDL (Web Interface Definition Language). WebIDL binds together C++ and JavaScript, and it doing so, introduces a few legacy quirks - but also allows for rich expression error-handling behavior, type checking and enforcement, inheritance, statics, etc.

Unless you are a (W3C) Spec Editor, you probably will never need to write WebIDL. However, if you've ever found yourself reading a W3C or WHATWG specification (e.g., the HTML standard), then knowing a little WebIDL can help you understand how JS interacts with the DOM.

Additionally, if you would like to extend the DOM through a "pollyfill" - then knowing how to replicate the behavior of WebIDL interfaces is crucial.

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