For Centos 5.4:
Firstly, install the dependencies:
# yum -y install perl-Net-SSLeay
Then download the rpm package and install it:
# cd /opt # wget http://sourceforge.net/projects/webadmin/files/webmin/1.500/webmin-1.500-1.noarch.rpm/download # rpm -i webmin-1.500-1.noarch.rpm
Then reach your management url:
https://your-hostname-or-ip:10000 The default user is setted to “root” and the password is your root account’s password.
For Debian 5.0:

Firstly, install the dependencies:
# apt-get install perl libnet-ssleay-perl [...]