Faction
Each connected player client allows control of one faction. All units and their sensory are shared among each other and the player client.
Structures of the same faction implicitly connect into compounds to share resources.
Auto-firing towers will use the sensory of any other unit of the same faction or alliance to extend their own vision.
Players are given control of a new faction during their first connection.
A secret key is transferred that allows the client to resume control of this faction later on.
Upon reconnection, players may choose to resume their faction or create a new one.
However, only one key per planet ID is locally preserved.
Alliances
Since v0.7.0, factions may form alliances via the factions window (Main menu->Game->Show factions).
Alliances are currently invite-based, and share sensor data amongst all members.
Offensive units will never automatically target units of allied factions.