Calcite Download

The vanilla server. Rebuilt in Rust.

Calcite plays exactly like the official Java Edition server, bugs included. It just needs a fraction of the memory, and no Java at all.

Downloads How it works
Red and orange autumn trees over rolling hillsA lush cave with hanging glow berries and vinesA village house beside a grassy hill and a riverLava falling into a dark deep caveRounded red and yellow autumn treesTall stone cliffs topped with dark oak forest and giant red mushroomsA dirt ridge with autumn trees and a far towerA large cave with red and pale yellow blocks and spiky plants

Same game. Less hardware.

207 MB
for a world with 2,000 mobs. Vanilla needs 3,131 MB.
10 s
to generate 1,024 new chunks. Vanilla takes 37.
80 % CPU
of one core with 50 players online. Vanilla needs 115.
  • Core i5-8500Intel, 6 cores at 3.0 GHz
  • 16 GBof RAM
  • NVMe SSDSamsung PM981, 512 GB
  • Debian 13Linux 6.12

Who needs 3 GB?

Both servers ran the same flat world on the same machine. Each block is 32 MB of memory.

Calcite 207 MB
Vanilla 3,131 MB

1,024 chunks in 10 seconds

We force-loaded a 32 by 32 chunk square of a brand new world on both servers. Calcite was done in 10 seconds and peaked at 316 MB. Vanilla took 37 seconds and 1,093 MB.

Calcite 10.0 s
Vanilla 37.2 s

Is it really the same?

Every change plays the same scene on the real vanilla server and on Calcite. Then we compare every packet the two send back. If one byte is off, the change doesn't go in.

/damage Victim 100 minecraft:magic
  1. damage_event type 27
  2. player_position 7.5 -60.0 1.77
  3. entity_event 35
  4. set_entity_data 6=3 9=1
Every packet matches. The change goes in.

Bring your world

Drop Calcite into the server folder you already have. Nothing to convert, and you can switch back to vanilla any time.

  • Worlds and player data, upgraded from old versions like vanilla does
  • server.properties, ops, bans and the whitelist
  • Datapacks and server resource packs
  • RCON, query, the management API and the server window

Not in Calcite: plugins and mods, JMX monitoring and experimental features.

my-server
  • world
  • banned-ips.json
  • banned-players.json
  • eula.txt
  • ops.json
  • server.properties
  • calcite-server
  • usercache.json
  • whitelist.json

Up and running in a minute

  1. Download it

    One file. There's nothing else to install.

    Downloads

  2. Put it in your server folder

    Next to your world and server.properties. Starting fresh? It makes them for you.

    chmod +x calcite-server

  3. Start it

    The first run stops to ask you to accept the EULA in eula.txt, just like vanilla. Leave out nogui to get the server window.

    ./calcite-server nogui

Questions

Can I use plugins or mods?

No. Calcite is vanilla, so it runs what the vanilla server runs: datapacks and resource packs.

Java or Bedrock?

Java Edition. Players join with the normal game, no mods needed.

Do I need Java?

No. Calcite is a single native program.

Is it faster?

Yes. It uses far less memory, generates new chunks several times faster, and with 50 players online it needs about 30% less CPU. Each tick takes 34 ms where vanilla takes 41.

Can I go back to vanilla?

Any time. Calcite saves worlds in vanilla's format, so the vanilla server opens them as they are.

Windows or macOS?

Not yet. Linux x86-64 only for now.