April 23rd, 2008 | Published in Google Webmaster Central
When we originally launched Sitemaps, we included support for the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) 2.0 protocol, an interoperability framework based on metadata harvesting. In the meantime, however, we've found that the information we gain from our support of OAI-PMH is disproportional to the amount of resources required to support it. Fewer than 200 sites are using OAI-PMH for Google Sitemaps at the moment.
In order to move forward with even better coverage of your websites, we have decided to support only the standard XML Sitemap format by May 2008. We are in the process of notifying sites using OAI-PMH to alert them of the change.
If you have been using OAI-PMH as a Google Sitemap feed, we would love to see you adopt the industry standard XML Sitemap format. This format is supported by all of the major search engines and helps to make sure that everyone is able to find your new and updated content as soon as you make it available.
If you have any questions regarding the move to XML Sitemap files, feel free to post in our Google discussion group for Sitemaps.