"System Administrators (SAs) need a set of tools with which to
manage their often unmanageable systems and environments*. These
ten essential Linux administration tools provide excellent support
for the weary SA. Those listed aren't your standard list of tools
deemed essential by industry bystanders. These are tools that have
proven track records and have stood the test of time in the data
center.
1. Webmin - Webmin is the ultimate web-based management platform
for Linux and several other operating systems. Written in Perl, it
simplifies and streamlines standard administrative tasks.
Additionally, Webmin helps you configure very complex
implementations of Apache, MySQL and SendMail. If you haven't
experienced Webmin, you should, it's the essential administration
tool.
2. byobu - If you're a screen user, byobu is the next step."