RSS is a family of syndication formats that traces its roots far back in the history of computer science. The most widely used version of RSS is 2.0. I wrote the spec for that version, created software that read and wrote it, and helped content providers, notably the NY Times, get online with it.
We also adapted RSS to transport what I thought of as "audio blog posts." Working with Adam Curry and others, this became podcasting.
There are lots of different kinds of software that produce RSS and consume it. Each of them has its own name. But they are not RSS. They are applications that do stuff with RSS. That, imho, is a very important distinction.