There's a link to worklets' explainer in CSS Layout API explainer, but there's no such file in the repo: > See the worklets [explainer](../worklets/EXPLAINER.md) for a more involved explanation of worklets. https://github.com/w3c/css-houdini-drafts/blob/master/css-layout-api/EXPLAINER.md (I haven't send a PR because I'm not sure it's important.)