There is only one file type that uses the .OPML extension:
Outline Processor Markup Language File
Outline document written in OPML (Outline Processor Markup Language); used to exchange lists of Web feeds (such as .RSS files) between Web feed aggregators; also used for other general outlining purposes.
Each OPML file contains the following XML elements:
- OPML version - e.g. "1.0"
- Head - contains metadata that describes the content
- Body - contains the content of the outline
- Outline - contains a line in the outline
Updated: August 11, 2019