For testing purposes you should use the OSI Client at the moment.

You can run the original (OSI) client under GNU/Linux with the help of Wine (see http://appdb.winehq.org/appview.php?iAppId=228).

There was a download called uoml_setup.exe called Mondain's Legacy which contains Client Version 4.0.11c (Patch 0).

You can download a client from http://largedownloads.ea.com/pub/uo/uoml_setup.exe http://largedownloads.ea.com/pub/uo/setup-1.46.0.3.exe. After installation you have a client v6.0.1.10 (Patch 72).

There also seems to exist an god client: http://necrotoolz.sourceforge.net/kairpacketguide/godcli.htm

The current version (build 72) is based on QT4.

apt-get install libqt4-dev qt4-qmake libopenal-dev libalut-dev

Perhaps there are some minor changes in uoclient.pro nessesary.

qmake
make

After compilation the file uoclient exists in the current directory. Move it to the release directory and start:

mv uoclient release
cd release
./uoclient

You get an error, but the configuration file config.xml is created. Update that file to fit your needs: edit your server IP and the path to the UO installation. After that you can copy the file to your home directory and afterwards start the client

mkdir ~/.UO
mv config.xml ~/.UO/config.xml
./uoclient -c ~/.UO/config.xml

To be standards compilant one should move uoclient to /usr/local/bin, the UO-files should stay in /usr/local/share/UO, the wolfpack stuff perhaps in /usr/local/share/wolfpack and so on

see: http://www.iris2.de/