The current website pages are using HTTP protocol links. Since many (most?) are using HTTPS (and browsers are tending to prefer this), the links should probably point to HTTPS instead.
This will require ensuring the HTTPS certs are renewed automatically, that all URLs are configured for this, and updating the gemtext to html conversion tool.
Links on retroforth.org are now preferring https over http. I still need to verify that the automated cert renewal is working.