To install webmin in ubuntu:

cd ~/Downloads/
wget http://prdownloads.sourceforge.net/webadmin/webmin_1.650_all.deb
sudo apt-get install perl libnet-ssleay-perl openssl libauthen-pam-perl libpam-runtime libio-pty-perl apt-show-versions python
sudo dpkg --install webmin_1.650_all.deb

Webmin is now accessible from https://localhost:10000 using the root username and password.