Install stable version
<?php
$URL="https://raw.githubusercontent.com/panticz/installit/master/install.xbmc.sh";

echo "wget $URL -O - | bash -";
echo "<div><pre>";
</pre></div>

$c = curl_init();
curl_setopt($c, CURLOPT_URL, $URL);
curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);

echo htmlspecialchars(curl_exec($c));

curl_close($c);

echo "";

?>

install unstable version

wget http://installit.googlecode.com/hg/install.xbmc.sh -O /tmp/install.xbmc.sh

bash /tmp/install.xbmc.sh -u

Unofficial PVR repository

sudo add-apt-repository ppa:lars-opdenkamp/xbmc-pvr

XBMC standalone

sudo apt-get install -y xbmc xbmc-standalone

Configuring a Wii Remote
http://www.mini-itx.com/projects/xbmc-ion/module/6