Cubelands (the indie voxel sandbox) does not have official online multiplayer support. It is a single-player experience.
Community Workarounds
Modded Servers / Custom Clients: Small communities have created custom server software (often via Discord/forums) enabling multiplayer. These are unofficial, unstable, and require specific client versions.
World File Sharing: Players manually share save folders (located in `%appdata%\Cubelands` or install dir) to collaborate asynchronously—one builds, sends file, other continues.
LAN / Hamachi / Radmin VPN: Some mods enable LAN play; tunnel via VPN for internet play.
Better Alternatives for Voxel Multiplayer
Minecraft (Java/Bedrock): Official servers, Realms, massive modding.
Minetest (Free/Open Source): Engine with many games/mods; native multiplayer.