Here is a list of free and paid control panels that are available for Ubuntu server
Free CPanel Alternatives
web://cp
web://cp was where it all seems to have started for much of the open
source world. It was written in php and the aim of it's single
developer was to make a good quality control panel.
web-cp is an Open Source solution taking up the torch where web://cp
stopped and is a direct continuation of that project. Like the
original this is written in php and so should put little additional
stress on a server. This might be good for you if your server is a
little lacking in the power needed to run piles of additional
software.
FlexCP
FlexCP is an Open Source solution and so is likely to improve in
proportion to the number of users. It can be obtained under the GNU
GPL version 2 from sourceforge.net. It is a redevelopment of
"web://cp" and as of writing had not released any file packages.
Cube Panel Lite
This is the stripped down version of the non-free Cube Panel. Being
closed source there is a lot less that can be easily researched on the
subject. I can however tell you that you will be limited to one server
and 30 domains. After that yo will be looking for an upgrade or
another free alternative.
VHCS
VHCS is an open source solution released under the Mozilla Public
License 1.1 (MPL 1.1) and it appears to be a live and ready to go open
source solution. For mission critical servers this might be the choice
of system for this reason only. It is a sourceforge.net project so
downloading should be simple even if installation is not.
And of course
Webmin
Webmin is a free and impressive looking suit of control panel
packages. It is free and open source solution licensed under the BSD
License according to sourceforge.net. Much like the Fedora and Red Hat
relationship there is a non-free version too. The GNU GPL is also used
which is a bit confusing for the fussy.
Non-Free CPanel Alternatives
Plesk
After CPanel this is possibly the next biggest system used.
Cube Panel
While "not at all" playing off the CPanel naming this is a
commercially viable package. Like CPanel there are three levels of
management allowing for reseller accounts but also like CPanel you are
going to pay for this. The key advantage here is that you an get a
free 20 day trail version to test out prior to purchase. You may also
find that the "lite" version has everything you need.
Ensim pro
Direct Admin
While "not a free offering" the lifetime unlimited license is a mere
US$299 which, right now, is arround UK£147 (give or take a bit). This
comes with 90 days of support which should be enough to get you up and
running. Alternatively you can pay by the month for ongoing support.
Virtualmin Pro
The pay for, super "pro" version of webmin's virtualmin for those that
want all the power. The webmin site says "Both the Pro and GPL
versions are built from the same codebase, so all bugfixes and some
new features go into both of them."
VHCS Pro
ServerPilot
ServerPilot is a SaaS control panel for developers hosting their
websites on Ubuntu servers. The basic server configuration and
security functionality is free. The paid plans offer advanced
features and monitoring.
Source:LordMatt