Horizon Server

A Minecraft: Java Edition 26.3 server written in Rust, built for Horizon players first: the fastest server we can make, with vanilla's rules. Horizon clients get extras through a fast path; vanilla Java clients can join too.

It reuses Horizon's vanilla-exact crates (world generation, block behaviour, protocol) from horizon-rust/horizon.

Status: design. The design, the measured baseline and the plan come first, in docs/design.md. No code yet.