RSS Guard 4.1.0 had been ported to ArcaOS, OS/2 and eCS.
RSS Guard is simple, light and easy-to-use RSS/ATOM feed aggregator developed using Qt framework which supports online feed synchronization with these services:
Tiny Tiny RSS,
Inoreader,
Nextcloud News,
Gmail API,
FreshRSS,
The Old Reader,
Bazqux,
Reedah,
Feedly.
It requires the Qt 5 libraries.