Mine[1] is rather tiny and simple. It is actually generated by the tree command in about a second. It's a port from the gopher protocol and is hosted by the venerable sdf.org[2]. I decided to pay an exorbitant $60 a year for an enhanced membership simply to have an https address and some other assorted goodies[3]...

[1] https://every.sdf.org/

[2] https://sdf.org/

[3] https://sdf.org/?tutorials/metaarray