GitHub's Web Component collection.
We have 16 open source custom elements:
An input element that validates its value with a server endpoint.
Auto-complete input values from server search results.
Copy element text content or input values to the clipboard.
A modal dialog that's opened with <details>.
A menu opened with <details>.
Attach files via drag and drop or file input.
Display elements in a subtree that match filter input text.
Backports native emoji characters to browsers that don't support them by replacing the characters with fallback images.
A custom element for cropping a square image. Returns x, y, width, and height.
A client-side includes tag.
Markdown formatting buttons for text inputs.
An input element that sends its value to a server endpoint and renders the response body.
An accessible tab container element with keyboard support.
Drag and drop task list items.
Activates a suggestion menu to expand text snippets as you type.
Web component extensions to the standard <time> element.