UCGO is an UC Gundam MMORPG which is no longer in service, it was shutdown in 2007.
This website UCGOSERVER.COM is a privately run server for UCGO being around since 2009. However since December 2019 it is no longer open to the public and has been made open source.
Source code for the server can be downloaded from the link in the menu. Together with the game client and anything else you need to setup your own UCGO server.
With the server source code you can setup a server for your own private single player use, in a local network just for PVP or public use like I did here.