Google Sitemaps and Tools

In June 2005, Google introduced a new service called Google Sitemaps (now known as Google Site Maps), which allowed webmasters to provide Google with indexing files that were beneficial for Google searches. Not long after, Yahoo! and Live Search also announced support for XML format sitemaps. This primarily introduces some overlooked aspects of Google Sitemaps and discusses various sitemap tools, such as: Is there a difference between ASP format and XML format sitemaps? Must the sitemap file format be XML? How can the validity of a sitemap be tested, etc.