Many web resources provide mechanisms for subscribing to changes in their content. However, this change information is only made available via a polling mechanism.
A number of people have proposed mechanisms for subscribing to updates to pages or feeds, however, a missing element of all these proposals is a subscription mechanism. Sadly, this means that every site supporting this feature will likely end up with a different implementation.
Get Pingd pour la mise à mort de la syndication... (à coups de XRDS, d'Atom et de web hooks, tout un programme)
This white paper recommends that the Intelligence Community, over time, move toward adoption of Atom Syndication Format as the Community’s standard XML-based language for syndication feeds. The paper compares Atom to the current de facto standard, RSS 2.0, and explains the many benefits to be gained by moving toward Atom.