SpanUI

SpanUI is a lightweight, open-source user interface library for building accessible web interfaces. It emphasizes semantic HTML, a small runtime, and a component model that can be used with vanilla JavaScript or TypeScript. The goal is to minimize JavaScript overhead while preserving rich interactivity.

History and scope: SpanUI was initiated by a small open-source team in 2019, with the first stable release in 2020. The project is maintained on GitHub under the MIT license. It targets modern browsers and provides progressive enhancement for accessibility.

Architecture and features: SpanUI components are exposed as custom elements (for example, spanui-button, spanui-card, spanui-grid) and are designed to work with plain HTML, augmented by optional JavaScript initializers. The styling uses CSS variables and a theming system to support visual customization. Accessibility is a design priority, including keyboard navigation, appropriate ARIA roles, and focus management.

Usage: Developers include the spanui runtime in their page and use the provided custom elements in their markup, with optional data- attributes for configuration. A separate CSS file supplies the base styles and themes; the API is designed to be minimal and predictable.

Evaluation and ecosystem: SpanUI is popular with small projects and teams seeking a lightweight alternative to heavier frameworks. Its plugin ecosystem is smaller than that of large libraries, but it benefits from simple integration with existing HTML. Performance is a strength due to its small footprint and lack of heavy virtual DOM.