Federated Wiki sites share pages circulating within a creative commons. A single-page browser application can read from many sites at once and save changes in that browser. Users who host their own sites can login there to have their edits shared back to the federation as they edit.
An outpost is an applications that deviate substantially from the routine behavior of wiki while still cooperating in the federation. Typically these are situated in order to access unique features in their environment or possibly to explore emerging technology expected to become the new norm once proven.