John Panzer, the Google engineer who first proposed Salmon, notes that the protocol also includes ways of checking the identity of people making comments. While it's possible to use a pseudonym to post, he says, it's not possible to forge someone else's signature. This feature would help prevent spammers from using the protocol as yet another means of distribution.

Earlier open standards helped make it easier for users to participate on sites across the Web by making it simple to transfer things like profile information and lists of friends, says Joseph Smarr, chief technology officer at Plaxo, a company in Mountain View, CA, that synchronizes contact information between Microsoft's Outlook, other desktop e-mail programs, and a number of Web services. The new generation of protocols are solving the problems created by that success, he says, adding, "Now the question is, how do you end up not having the conversation be totally fragmented?"

Salmon does raise privacy questions, Smarr says. For example, it's unclear whether users will be comfortable seeing their comments distributed to a wide variety of sites.

Marks says he's seen a lot of concern recently as more sites have moved toward sharing information through business deals rather than through open standards. He says he remains optimistic about the new set of protocols, but adds, "Writing standards is easy. Getting people to adopt them is hard."

Engineers have built a demonstration of Salmon, but the protocol is too new for any site to have formally adopted it so far.