Abstract : Structured documents associate explicit semantics with content, but authoring rigorously structured documents is a very difficult task. We present a new approach to this issue that adds schema-level information to the popular web formats. This makes editing highly structured documents easier, while ensuring that documents are valid. It is also an easy way to publish semantically rich documents on the web. The impact of this approach on authoring tools is discussed and its implementation in the Amaya editor is briefly presented.