I heard a bit about these, and wanted to drop info on how to setup a Private FFXI Server, and be a GM, etc.
I shall prolly give this a try, as I want to super solo stuff.
How do I setup pXI so that it works?
1) Install mySQL and run the Server Config Wizard. (If you already had mySQL, run the wizard and select Reconfigure Instance.) Select Detailed Configuration, then go through the next few screens until you see the option Disable Strict Mode. You must UNCHECK this box, or else you will get stuck on character creation. You may set a password for your server if you want, but remember this password for later.
2) Install SQLyog and run a new connection. The name is root, port is 3306, and the password is whatever password you set in step 1. Go to the file menu and select DB, then click Create New Database. Name it pxidb. Leave SQLyog open for now.
3) Unzip the pXI release to wherever you want. Replace the client.exe with the new one in the second link. Unzip pxidb in the misc folder. Now go back to SQLyog and click on pxidb and press Ctrl-Shift-Q Find pxidb_svn.sql and press Execute. This will take a few minutes.
4) While that is going, you can open pxi.ini and edit the settings. Change SERVER to localhost, PORT to 3306, USER to root, PASS to your password from step 1, DATABASE to pxidb, SERVIP to 127.0.0.1, and UDPPORT to 54230. Many of these settings may already be right.
5) This step is the trickiest. Go to Windows/system32/drivers/etc/ and select the file called hosts. Note that this file does NOT have a file extension. You can open it with notepad. You’ll need to erase the bottom few lines (the ones without the # in front, and change it to this:
Save it and make sure it saved the changes. Note that if POL or FFXI is on at this point you must shut it down and restart it. By now SQLyog should be done importing your database, you can close it now.
6) Make sure POL and FFXI are set to windowed mode, and run POL. Log in and run FFXI. When you get to the blue screen asking you to accept/decline, STOP. Now run pxi-server0.6.0b.exe, and client.exe. Now you may hit Accept. If you set everything up right, you should be able to create as many as 16 characters and play!
Keep in mind, this is for a Local Only Server. SE would be super mad if this was spawning a custom remote server setup.
Source: FTB Threads