The Pen is a classic prison server that feels like the older days where you actually have to grind. You start with basic tools and leather armor and you work your way up through ranks from A to H then Parolee and Citizen.
The big thing here is risk. You smelt your ores and you have to walk through PvP zones to sell them at the Commissary so it is not just instant money. Swords and potions are illegal too and the Guards will fight you if they catch you with them. If you act up you can even get sent to solitary.
There are lots of ways to make money besides mining like custom fishing and growing special illegal plants in your cell for profit. You can rent a prison cell or a plot to store items build and even run your own shop. There are quests for extra cash and special items plus an auction house bounties and parkour around the prison. After you hit top rank you can prestige for special rewards and you can also become a Parolee and leave the prison to build a farm for more money.

