Finnix is a small, self-contained, bootable Linux CD distribution ("LiveCD") for system administrators, based on Debian testing. You can use it to mount and manipulate hard drives and partitions, monitor networks, rebuild boot records, install other operating systems, and much more.
The GNOME NetworkManager is a set of co-operative tools that make networking simple and straightforward. Whether wireless or wired, NetworkManager allows you to quickly move from one network to another: once a network has been configured and joined once, it can be detected and re-joined automatically at a later date. It was designed to auto-detect as much information as possible, seamlessly switches connections when necessary, and provides immediate feedback of the network state to users and applications.
BitNami RubyStack provides a fast, easy way to develop and deploy Ruby on Rails applications. It includes Ruby, Subversion, MySQL, SQLite, ImageMagick, and several Ruby Gems, and will optionally install Apache 2.2 with rewrite and proxy support. It supports Windows, Linux, and OS X, so you can share the same Rails environment on multiple platforms.
TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
Virtual Appliances are nano-sized virtual machines for deploying instant infrastructure and applications. They are Ubuntu Server Edition 8.04 based and available for VMware, QEMU, KVM, Parallels, Xen, Virtual Iron, Virtural PC, and Virtual Server. Available Virtual Appliances are a LAMP Server, LAPP Server, Apache Tomcat Server, and Cacti Virtual Appliance. These are the smallest, most functional, and easiest to use Virtual Appliances available. They are certified for use on VMware and Parallels.
TurnKey Joomla Appliance is a server appliance for the Joomla! content management system. It is designed to be easy to use and easy to maintain. Security patches are automatically installed. It provides a Web management interface, configuration console, and AJAX Web shell. To minimize footprint the appliance is built from the ground up with the minimum required components. It runs everywhere thanks to multiple build formats, including an installable live CD, a VMDK with OVF support, and an Amazon EC2 AMI.
The IP Masquerade HOWTO is the document that contains instructions on understanding, configuring, and troubleshooting NAT or Network Address Translation for Linux. It covers topics such as IPTABLES, PORTFW, IPCHAINS, IPFWADM, stronger packet firewalls, multiple network segments, and configuring many client operating systems. It also has an extensive FAQ and troubleshooting section.
scponly is an alternative "shell" of sorts for system administrators who would like to provide access to remote users to both read and write local files without providing any remote execution priviledges. Functionally, it is a wrapper around the ssh suite of applications. It is typically used by creating a user whose shell is set to scponly. This user can neither login interactively nor execute commands remotely, but it can use scp and sftp to download and upload files to the computer, governed by the usual Unix file permissions.