If you're using Germinal as your Gemini server, maybe you are interested in a small handler I wrote.
I tried literate programming for the first time, as I wanted to gather some info in an Org file, and then I thought, why not put the code here as well and just tangle it, like with my dotemacs.org file? And as, if you are interested in Common Lisp you probably are using Emacs already, you might as well have this with documentation included, here is the org file.
Oh yes, what does it do, anyway? The handler compiles a list of all external links in all .gmi files of a capsule, so that visitors have an easy escape route or other places to go after they read all your glorious content.
If you use my Elpher configuration, you can watch it right in elpher, syntax highlighting and all. You can't tangle the code before you saved, though, at least I hope so. ;)