Yahoo YQL:
select * from xml where url = 'https://news.ycombinator.com/rss'
callback
https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20xml%20where%20url%20%3D%20'https%3A%2F%2Fnews.ycombinator.com%2Frss'&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=mycallback