Pretty cool example of Lisp's capabilities.

When trying to create feeds from webpages in the real-world, there are plenty of pitfalls involved, for example: handling JavaScript content, graceful retries, bypass IP blocks, throttle & rate-limit requests, accessing public social media (Facebook, Twitter, Google) etc.

At Feedity (https://feedity.com), we've developed our own little system over the years using .NET (C#) and node.js, with a bunch of tweaks and optimizations, for generating custom feeds from public webpages.