IPKG

ipkg, or the Itsy Package Management System, is a lightweight package management system designed for embedded devices that tries to resemble Debian's dpkg. It is used in the Unslung operating system for the Linksys NSLU2 (Optware), in OpenWRT, Openmoko, WebOS, Gumstix, the iPAQ, QNAP NASes, Synology NASes and elsewhere. (Source: Wikipedia)

Note
IPKG has already been added to the PHP Installer and this guide should only be consulted if you want to learn how to set it up manually.

Here is a little step by step guide to get ipkg on your e-TRAYz. Thanks to meni for posting this in the Xtreamer Forum. Before starting, make sure SSH in your e-TRAYz settings is enabled and use Putty to login as root user. The root password will be the same as your sysadmin user. The following commands one by one will install and update ipkg:

cd /opt
mkdir tmp
cd tmp
wget ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/unstable/ipkg-opt_0.99.163-10_arm.ipk
tar -xOvzf ipkg-opt_*_arm.ipk ./data.tar.gz | tar -C / -xzvf -
mkdir -p /opt/etc/ipkg
echo "src cross http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/unstable" > /opt/etc/ipkg/armel-feed.conf
echo "src native http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/native/unstable" >> /opt/etc/ipkg/armel-feed.conf
/opt/bin/ipkg update

This will get you the latest ipkg on e-TRAYz. To see what packages are available use the following command:

/opt/bin/ipkg list

Don't get overwhelmed by the list. Check it carefully and pick out the ones you really need. Let me know in the official Xtreamer Forum if you found something interesting... and before I forget: the first thing I install on all my servers is Midnight Commander, a must have file manager and editor and more...

Install Midnight Commander

/opt/bin/ipkg install mc

Happy exploring!