Bing announced, on its Bing Webmaster Blog, a new feature that helps webmasters create two types of XML Sitemaps.
Bing created a server-side application that works on both IIS and Apache servers that helps you create a comprehensive Sitemap and, also, a recently updated Sitemap. The binaries can be downloaded at the Microsoft download site.
How do the two Sitemap files differ? The first is a comprehensive Sitemap of all URLs seen in server traffic, and the second is a Sitemap dedicated to store URLs that have changed recently.
Duane Forrester explained:
Having both comprehensive and delta Sitemaps provides you with significant benefits, as you will always have a full, up-to-date list of all URLs on your website that search engines can use for deep crawl, as well as a concise Sitemap of URLs that were modified recently, which search engine crawlers can prioritize. This can help in keeping bot traffic bandwidth down. In addition, the Sitemap Plugin automatically adds values to your Sitemap, and generates values to the Sitemap based on how popular your URLs are.