The good people at Ask.com pinged me this morning that Google, Yahoo!, Microsoft Live Search and Ask.com announced support of autodiscovery for Sitemaps today.
WebProNews published an announcement about the search engines Google and Yahoo agreeing to work on a common sitemaps standard and the launch of sitemaps.org at the WebmasterWorld Pubcon conference in Las Vegas last year.
The new open-format autodiscovery allows webmasters to specify the location of their sitemaps within their robots.txt file, eliminating the need to submit sitemaps to each search engine separately. The updated Sitemap protocol has benefits for site publishers, the search engines as well as searchers. Ask.com is also supporting manual submissions of sitemaps via a ping url.
Find more coverage on this over at Search Engine Land, “Search Engines Unite on Sitemaps“.