Really Simple Syndication

RSS is a family of Web feed formats used to publish often updated content such as blog entries, news headlines or podcasts. An RSS document, which is called a "feed," "web feed," or "channel," contains either a summary of content from an associated website or the full text. RSS allows people to keep up with their favorite websites without manually checking them. This flow of content between websites and users is called "web syndication".
RSS content can be read using software called an "RSS reader," "feed reader", or an "aggregator." The user subscribes to a feed by entering the feed's link into the reader or clicking an RSS icon in a browser that begins the subscription process for the online. The reader often checks the user's subscribed feeds for new content, downloading any updates it finds. This content is stored in a standard XML file that many different computers and programs can understand. This file tells the programs how to show the content to the user.
The letters "RSS" are used to refer to any of these formats:
Really Simple Syndication (RSS 2.0)
RDF Site Summary (RSS 1.0 and RSS 0.90)
Rich Site Summary (RSS 0.91)
RSS is also used on exchanges. An example of using RSS is Carbon Place, which uses it to show orders to the public.
History
There were other similar formats before RSS that were not as popular. The first one was the Meta Content Framework made in 1995 by Ramanathan V. Guha and others at Apple Computers.
The first version of RSS was called RDF Site Summary. It was made by Dan Libby and Ramanathan V. Guha at Netscape and made public in March 1999. This became RSS 0.9. In July 1999, RSS 0.91 was created by Dan Libby, which got rid of some features that weren't useful. It also added elements from Dave Winer's news syndication format. Libby renamed the format from RDF to RSS Rich Site Summary and planned how it should be made better in the future.
In 2001, the company was restructured by their owner, AOL, and no longer supported RSS. After that, the format was being developed by the RSS-DEV Working Group and Dave Winer. Winer was the first to write programs that could read and write RSS and were not made by Netscape.
RSS 1.0 was produced in December 2000 by the RSS-DEV team, which included representatives of O'Reilly Media and Moreover Technologies. This version added support for XML namespaces and RDF, which was previously removed in RSS 0.91. This version also changed the name back to "RDF Site Summary" and added new elements that help describe content, such as Dublin Core.
Also in December 2000, Dave Winer released RSS 0.92. It added the enclosure element, which could be used to include sound in RSS feeds. This feature is one of the origins of Podcasting. Winer also made drafts of RSS 0.93, which allowed many enclosure elements per an item element, along with RSS 0.94, but those versions were cancelled after being released.
In September 2002, Winter made RSS 2.0, the next major version of RSS. This version introduced the following changes:
Renamed the format to Really Simple Syndication
Removed the type attribute from the RSS 0.94 draft
Added support for namespaces, like in RSS 1.0 released by RSS-DEV
To make sure that old programs which only support RSS 0.92 still work with RSS 2.0, namespace support only applies to other content within the feed, not the elements themselves. Other formats such as Atom tried to remove this limitation, however it never caught on.