In direct contrast to a Permissioned Ledger, an Unpermissioned Ledger is a ledger that just about anyone can simply download. Any participant can submit messages for processes and even be involved in processes of authentication, verification, and consensus protocol for the determination of what the status of the blockchain should be.
The Unpermissioned Ledger can also employ another process to ascertain that state. Another efficient way to make use of the process is to enlist the assistance of an administrator of sub-group of participants. These types of systems are usually not controlled with participants only using pseudonyms.