Date: 2017-05-02
The interface for Web Share is now described at https://wicg.github.io/web-share/.
The basic Share API only allows share requests to be sent (this API does not provide the capability to receive share requests). For a follow-up plan to have websites receive share requests from the system, or other websites, see the Share Target API.
Examples of using the Share API for sharing can be seen in the explainer document.
Note: The Web Share API is the first concrete proposal of the Ballista project, which aims to explore website-to-website and website-to-native interoperability.