If you don't know what gists are from the get-go then that's where I'd start. Gists are a separate feature of GitHub where you can share code like if it's pastebin or other similar services, but tied to your GitHub account. This enables you to execute code from gists, which can be written in dozens of languages.

Here's a list of all the new fun ways HNers are using Gist ~ https://news.ycombinator.com/from?site=gist.github.com

I also didn't get what it does, just reading the homepage content and viewing the examples. And I know what Github gists are (I suppose, are the just text files?)

It does things with GitHub gists, i.e:

  - Upload directory snapshots
  - Publish & host static websites on a CDN
  - Create code tutorials
  - Create & Execute Apps in any of the supported languages

And view it from https://gist.cafe/<gist-id> and anyone you share it with can click on the "Edit" icon to download & open it locally in VS Code or their file manager.

It runs small blocks of various types of code on a remote server and let’s you render/embed the results on your page.

The demo would probably work better if not for;

  exit code 134
  Unhandled exception.
  System.Net.WebException: The remote server
  returned an error: (403) rate limit exceeded.

It's like jsfiddle for multiple languages.