Summary

  • Google launched Sidewiki on 23 September 2009 as a browser sidebar for notes next to any webpage. Google ranked entries by its own signals rather than date and could show one entry beside other pages containing the same text snippet. The underlying site and the annotation venue had different operators.
  • A read-only API exposed entries by page or author; a November update added retrieval across a domain and RSS. In September 2011, Google said Sidewiki would be discontinued and its authors would have months to download their content.

A second column appeared without changing the page

Google's launch post invited readers to add information next to any webpage. The product lived in Google Toolbar for Firefox and Internet Explorer. Open the sidebar, and the page acquired a parallel conversation in the browser. The original page's HTML, its publisher's comments policy and its hosting bill did not have to change for a Sidewiki user to write there. A visitor using the Toolbar saw the extra column; a visitor without it saw the site as published.

That separation was the whole trick. Google did not need to ask each publisher to install a comment system. It could offer the browser user a place to speak about a page without placing that speech on the page owner's server. A useful correction to a tutorial, an argument about an article, or a welcome note from the site's own webmaster could all appear in this adjacent space. Its relationship to the page was supplied by the browser layer, not by a paragraph in the page itself.

The distinction also changed whose decision counted. A publisher could edit the page. A Sidewiki author could write an entry. Google determined the sidebar's presentation. In the launch announcement, it said entries would be ranked for usefulness rather than shown newest-first, using reader feedback, the author's earlier entries and other signals. The company even described moving an entry beside other pages that contained the same snippet of text. A note could follow a quoted passage across the web.

That was a more ambitious address than one page URL, and it made the matching and ranking machinery part of the conversation's editorial surface.

The public doorway was read-only

Google released a Sidewiki Data API on launch day. Developers could retrieve entries about a particular webpage or entries written by a particular author. The API was read-only at first. That mattered because a public retrieval endpoint can expose a collection to outside tools without handing those tools control over the service in which readers encounter it. A copy of an entry in another program still needed a way to know which page it was about, who wrote it and where Google placed it.

The 50-day update in November 2009 expanded that doorway. An application could retrieve entries across an entire domain, and users could subscribe to new entries by RSS. A site operator could monitor what Sidewiki users said next to any page on the site; the site still did not host the entries. Google singled out a Mayo Clinic welcome note as a special webmaster entry, an example of a publisher joining the neighboring conversation rather than absorbing it into the site.

The same update listed varied contributions, from programming tips to an online petition. They were chosen examples, not a census of who used the product. They do show the breadth of roles a sidebar could hold: teacher, critic, visitor, publisher. The API made the material legible beyond the Toolbar, while the Toolbar decided where an ordinary browser user would see it.

The landlord gave notice

On 2 September 2011, Google included Sidewiki in a list of products it would discontinue. Its explanation was a shift of attention toward broader social initiatives. Sidewiki authors, Google said, would receive further details and have a number of months to download their content. The notice did not give an exact shutdown day or an account of completed exports. What it did give was a change in control: the company that had installed the column next to other people's pages would now remove the service that made that column appear.

An export could preserve an author's sentences. It could not, by itself, keep Google's browser sidebar operating, preserve the order in which Google ranked entries, or make a future visitor see a note next to the same passage. Those were properties of a live service, not of the text alone. The page owner had not installed the venue, so keeping the original webpage online did not keep the annotation venue online. The contributor's writing and its place beside a page had been joined by Google's machinery.

This episode was brief and unusually explicit. Google built a parallel layer over the web in 2009, opened a read-only way to inspect it, widened that view to whole domains, and announced its retirement in 2011. Sidewiki showed how easy it was for a browser operator to add a public conversation next to a page at web scale. It also showed how quickly that conversation's placement could become a product-lifecycle decision made elsewhere.