The XML standard introduced some years ago has greatly changed the way data and information is distributed and exchanged between Web servers and computers connected to the Internet. RSS feeds are XML formatted data files that can be sent between Web servers and published immediately. RSS feeds are at the core of blog publishing. Most blog software has RSS feed option offering automatic creation of RSS feeds. Each RSS feed has its own URL that can be advertised in specialized directories, bookmarking services and specialized feed search engines. RSS feeds are read by Web users using feed readers and the user decides which feeds to subscribe to or read. Many say the RSS feeds are today's equivalent of an e-Mail newsletter and that RSS feeds will eventually replace most of them.