RSS was first invented by Netscape. They wanted to use an XML format to distribute news, stories and information. Netscape refined the version of rss and then dropped it. Userland Software to control of the specficiation and continued to develop it releasing a newer version. A non-commercial group picked up RSS at the same time and based on their interpretation of the Netscapes original concept of RSS they too released a new version. UserLand was not happy with the non-commercial version and continued development of their own version of RSS (Really Simple Syndication), eventually UserLand released RSS v2.

The History of RSS