The purpose of the Open UI, a W3C Community Group, is to allow web developers to style and extend built-in web UI components and controls, such as <select> dropdowns, checkboxes, radio buttons, …

Carbon is IBM’s open-source design system for products and experiences. With the IBM Design Language as its foundation, the system consists of working code, design tools and resources, human …

The <menubar> element represents an in-page group of <menuitem> elements that can either invoke commands or open submenus of commands. It defaults to a horizontal orientation, and its child …

Aug 5, 2025 · There are many useful use cases for offering a hovercard on anchors, such as signalling that they are external, or that they will open in a new window, or to show preview information (think: …

The Open UI Community Group is tasked with facilitating a larger architectural plan for how HTML, CSS, JS, and Web APIs can be combined to provide needed technology so web developers can create …

Feb 20, 2025 · When the dialog is open the button will have aria-expanded="true", when closed, aria-expanded="false". This will be recomputed whenever the dialog changes state, such that the button …

There are several ways to “open” an openable, and they are discussed in this section. When any of these methods are used to open an openable, it will be made visible.

This document covers how Open UI works, including guidance on how to work on standards with open UI, and norms about how Open UI works with WHATWG/HTML, CSS WG, ARIA WG, WPT, and …

For the purposes of Open UI, we consider a Web Component to be an implementation. We still distinguish between a “Web Component” and a “graduated” component, because of the different …

In an exclusive accordion, opening one of the items closes any existing open item. Some exclusive accordions are even more specific and at any moment in time exactly one disclosure widget is open.