Facepunch Studios' Rust, hosted on Ubuntu and supporting up to 20 players. Intended as a friendly PvE experience, with minimal decay, no radiation, and player whitelisting.
Mojang's Minecraft, hosted on Ubuntu and supporting up to 10 players. No mods, no tweaks, just player whitelisting.
System Era Softworks' Astroneer, hosted on Windows and supporting up to 8 whitelisted players.
Previously hosted:Windward (by Tasharen Entertainment)
Fornax Gaming is a division of Arcoba Labs, established to provide hosting services for a select gaming community.