The /hypertext directory on this server contains a 1992 partial snapshot of http://info.cern.ch, the first WWW site. This snapshot was obtained from the W3C Historical Archives, and has been merged with additional contents from the CERN httpd 3.0A distribution archive in order to fix some broken links. "The World Wide Web project" is a good page to start browsing from.
The particular server hosting this page is a containerized instance of the 3.0A httpd, assembled in 2020 -- 30 years after Tim Berners-Lee began development on the software. Only three lines in the 1996 code were changed, in order for the software to compile in a modern Linux environment.
A command-line HTTP client such as curl can be used to inspect the headers sent by this server. Note the "Server: CERN/3.0A" header, the "HTTP/1.0" version, and the nonstandard "Document follows" reason phrase after the 200 status code: