Simple example of a canister that publishes an RSS feed.
Go to https://vo3eu-eyaaa-aaaak-qawba-cai.raw.ic0.app and click on "Subscribe to feed".
The RSS Feed is available at https://vo3eu-eyaaa-aaaak-qawba-cai.raw.ic0.app/feed.rss
You can validate that the canister publishes a proper RSS feed with the W3C Feed Validation Service.
The canister exposes a function add_item(item: FeedItem)
to push new items to the RSS feed.
You can use Candid UI to add a new item: https://a4gq6-oaaaa-aaaab-qaa4q-cai.raw.ic0.app/?id=vo3eu-eyaaa-aaaak-qawba-cai