Server Compatibility 
Gate is compatible with many Minecraft server implementations. The expectation is that if the server acts like vanilla, Gate will work, and we make special provisions for modded setups where we can.
Gate is compatible with Minecraft 1.7.2 through the latest version and we maintainers update Gate as soon as a new Minecraft version is released.
Paper Recommended 
We highly recommend using Paper for running a server in most cases. Gate is tested with older and most recent versions of it.
You can use modern forwarding (like Velocity does) if you run Paper 1.13.2 or higher. If you use Paper 1.12.2 or lower, you must use legacy BungeeCord-style forwarding.
Spigot 
Spigot is not well-tested with Gate. However, it is based on vanilla and as it is the base for Paper, it is relatively well-supported.
Spigot does not support Gate/Velocity modern forwarding, but does support legacy BungeeCord forwarding.
Forks of Spigot/Paper 
Forks of Spigot are not well-tested with Gate, though they may work perfectly fine.
Proxy-behind-proxy setups 
These setups are only supported with Lite mode or Connect enabled!
You are best advised to avoid other kinds of setups, as they can cause lots of issues. Most proxy-behind-proxy setups are either illogical in the first place or can be handled more gracefully by purpose-built solutions like Connect or Lite mode.
 Gate Proxy
Gate Proxy