I am writing an RSS feed (for fun) and was looking at the spec here.
RSS is a dialect of XML. All RSS files must conform to the XML 1.0 specification,
Are there programs that can aggregate/understand this format.
You can use XSLT 3.0 to transform XML to JSON and back to XML again. More info on how to accomplish the transforms to JSON here:
https://www.xml.com/articles/2017/02/14/why-you-should-be-using-xslt-30/.