Bliz is primarily a server for the Gemini protocol. It was totally designed with Gemini in mind.
Bliz will serve Gemini on port 1965, as per the spec. The port can be customised.
In commit 3d1b5c7, minimal support for two other protocols was added.
Before the Gemini spec was written, Solderpunk wrote about an alternative idea for an even further stripped down Gemini. Some call this protocol Mercury.
Mercury was never written into a spec or implemented in any clients. One of the Gemini features it removes is TLS. Some enthusiasts designing software for ancient hardware might find this notable.
Bliz by default will serve Mercury on port 1964 (there is no canonical port). You can customise this or disable it in `personal/config.fish`. Bliz treats Mercury as if it's unencrypted Gemini, keeping everything else the same, including the same two-digit status codes.
Solderpunk on the Mercury protocol
Spartan is another alternative protocol idea. It's similar to Mercury, in that no TLS is involved, but it has a spec and the request line is not compatible.
Bliz has bare-bones support for Spartan. It converts read-only Spartan requests into Gemini requests, then passes them to the regular Gemini processing system.
The Spartan spec says to use port 300, but binding to this port requires root access, so Spartan support is disabled by default. You can enable it by editing `personal/config.fish` and choosing a port.
Read about Spartan over Gemini