pgrust is a Rust rewrite of PostgreSQL targeting compatibility with Postgres 18.3 — disk-compatible, boots from existing data directories, and matched Postgres's expected output across >46,000 regression queries and now reportedly passes 100% of the regression suite. The newer implementation uses a thread-per-connection model and claims large performance gains (≈50% faster on transactional workloads, ~300× faster on analytical workloads) but is experimental, not yet production-ready, and lacks full extension compatibility.