Vienna is an RSS and Atom feeds aggregator for macOS. It is an open-source software and can be easily installed using Homebrew on any Mac. If you have not installed Homebrew on your Mac then you can follow very easy instructions from how to install Homebrew package manager on Mac.
Once you have Homebrew installed, you can open Terminal and give the command brew install –cask vienna. This will download and setup Vienna on your Mac. Afterwards, you can launch Vienna from Finder menubar from under Applications. The app comes with many different feeds already added which might or might not be of any interest for you.
You can add a new RSS/Atom feed subscription easily on Vienna. For this you have to first click on the Add new icon in the toolbar and select New Subscription.
This will open a new window in which you have to enter the details fr your new RSS subscription. You have to choose the source as URL, enter the feed URL in the textbox and then click on the Subscribe button. You can find the feed URL for many of the blogs and news sites just by appending /feed/ to their base domain name. For other sites, you can check their homepage for specific links describing RSS/Atom feeds.
Once a new RSS feed subscription has been added, it will automatically fetch the feed and add it to Vienna. You can also manually fetch any of the subscriptions and check for any new updates. For manually checking for updates, you have to right-click on the subscription in the list and choose to check for updates.
Vienna RSS Reader can turn your Mac into a regular news tracker. You can keep up with hundreds of blogs and news sites in a matter of minutes. It comes with an integrated web browser using which you can read the original longer versions of the articles of any RSS feeds.
You can find more information about Vienna RSS/Atom Reader from https://www.vienna-rss.com/.