RSS Gizmos offers tools to create, find, and use RSS feeds better. Current tools available are:

• Kebberfegg -- Make keyword-based RSS feeds for a dozen different sources.
• WikiRSS -- Search Wikipedia for articles which contain RSS feeds as part of their Wikidata.
• CountryFeed -- Make country-specific RSS feeds using Bing News' loc: syntax.
• WordPress Preview -- Preview RSS feeds for WordPress.com tag and keyword searches.
• Bing News Query Checker -- Test three different queries for a Bing News RSS feed.
• RSS Feed Viewer -- Preview an RSS feed.
• Feed Freshness Checker -- Analyze up to 20 feeds at a time for post age and frequency.
• OPML Maker -- Turn a bunch of RSS feeds into an OPML file.
• OPML Peeler -- Extract the RSS feeds from an OPML file to display them and make them available as a CSV file.

See also:

https://github.com/adulau/rss-tools

A set of crappy Python scripts to handle RSS in an Unix way.

• rssfind.py is a simple script designed to discover RSS or Atom feeds from a given URL.
• rsscluster.py is a simple script that clusters items from an RSS feed based on a specified time interval, expressed in days. The maxitem parameter defines the maximum number of items to keep after clustering. This script can be particularly useful for platforms like Mastodon, where a user might be very active in a single day and you want to cluster their activity into a single RSS item for a defined time slot.
• rssmerge.py is a simple script designed to aggregate RSS feeds and merge them in reverse chronological order. It outputs the merged content in text, HTML, or Markdown format.
• rssdir.py is a simple and straightforward script designed to convert any directory on the filesystem into an RSS feed.