https://github.com/errantmind/faf is the fastest Rust static "web server" per the most recent TechEmpower Round 23 (Plaintext); it is purposely barebones (provide content via Rust callback!) The top 3 Composite scores are all Rust web frameworks, also not necessarily intended as general-purpose web servers.
I use https://github.com/sigoden/dufs as my personal file transfer Swiss Army knife since it natively supports file uploads; I will check out Ferron as a lighter reverse proxy with automatic SSL certs vs. Caddy.
This piece of fiber cable is the fastest static web server.
It is purposely barebones, but I bet you, it does almost nothing to reduce the delivery of a static website. The trick is: The website is already in its final state when it gets piped through the fiber cable, so no processing is required. The templating and caching mechanism is left open for most flexibility.
https://github.com/static-web-server/static-web-server wins the SEO (and GitHub star) battle, though apparently it is old enough to have a couple unmaintained dependencies.
I use https://github.com/sigoden/dufs as my personal file transfer Swiss Army knife since it natively supports file uploads; I will check out Ferron as a lighter reverse proxy with automatic SSL certs vs. Caddy.