To install OpenXenManager in Linux Mint/Ubuntu follows the steps below. The installation might be compatible with other Linux distributions.
Install the requirements.

apt-get install python-gtk2 glade python-gtk-vnc python-glade2 git

Download the source from the repo.

cd /usr/share
git clone https://github.com/OpenXenManager/openxenmanager.git

Create the start script.

vim /usr/bin/openxenmanager

#!/bin/sh
# OpenXenManager workaround for binary

test -d /usr/share/openxenmanager || exit 1;
cd /usr/share/openxenmanager;
python openxenmanager

Set the new file as executable.

chmod a+x /usr/bin/openxenmanager

To start openxenmanager run on the console below command as a user (not root)

openxenmanager

After you should see the interface of the program.