A lot of people don’t know this, but you can subscribe to subreddits using RSS by simply adding .rss at the end of the URL, e.g: https://reddit.com/r/socialism.rss and then you can add the feed to your favorite RSS reader. For example, there’s a great add on for Firefox and an Android app.
As far as I know, RSS feeds aren’t affected by the API changes. So if you use Reddit to catch up on the news, this is a great way to do that.
.rssoutputs it in a format that RSS readers recognize,.xmland.jsonare just different ways the page can be consumed, for example if you wanted to get the content through a service