NetNewsWire

 NetNewsWire  is an open source feed reader app for MacOS.

History
Brent Simmons originally developed NetNewsWire. It was later acquired by NewsGator, then Black Pixel. On 2017-06-01, Brent announced he was working on an open source feed reader,  Evergreen . 

On 2018-08-31, Black Pixel announced they could no longer maintain NetNewsWire and were returning it to Brent Simmons. Brent said that Evergreen 1.0 would be renamed NetNewsWire 5.0 and would remain open source. The github repository was renamed accordingly.

h-feed support
There is a github issue to add h-feed support: https://github.com/brentsimmons/Evergreen/issues/293
 * Brent Simmons indicated he would be adding support for h-feed in the 1.0 Alpha version