A suite of Unix command-line tools and a server designed to remotely administer the file systems of multiple Unix machines. For Mac OS X, there's also a graphical interface.

At its core, radmind operates as a tripwire. It is able to detect changes to any managed filesystem object, e.g. files, directories, links, etc. However, radmind goes further than just integrity checking: once a change is detected, radmind can optionally reverse the change.

Each managed machine may have its own loadset composed of multiple, layered overloads. This allows, for example, the operating system to be described separately from applications.

shush runs a command and optionally reports its output by mail based on the command's output, output size, exit code and/or duration.

It is a powerful wrapper around cron jobs which if properly configured will allow you to never get emails from cron jobs unless you need to see them!

shmux is a program for executing the same command on many hosts in parallel. For each target, a child process is spawned by shmux, and a shell on the target obtained one of the supported methods: rsh, ssh, or sh. The output produced by the children is received by shmux and either output in turn to the user in an easy to read format, or written to files for later processing, making it well suited for use in scripts.

shmux is a very powerful tool solving a simple problem in a generic way.

Ever been disconnected from your ssh session while in the middle of something? Ever wished there was a way to reconnect to that lost ssh session? Screen is for you..

Screen is a full-screen window manager that multiplexes a physical terminal between several processes. In fact, when you execute screen, you can imagine that you turned on another screen to the server that you're working on. You then execute your process on that virtual screen, detach your connection from it and return, whenever you please, to that screen in order to continue working.

Screen is a full-screen window manager that multiplexes a physical terminal between several processes, typically interactive shells. Each virtual terminal provides the functions of the DEC VT100 terminal and, in addition, several control functions from the ANSI X3.64 (ISO 6429) and ISO 2022 standards (e.g., insert/delete line and support for multiple character sets). There is a scrollback history buffer for each virtual terminal and a copy-and-paste mechanism that allows the user to move text regions between windows. When screen is called, it creates a single window with a shell in it (or the specified command) and then gets out of your way so that you can use the program as you normally would. Then, at any time, you can create new (full-screen) windows with other programs in them (including more shells), kill the current window, view a list of the active windows, turn output logging on and off, copy text between windows, view the scrollback history, switch between windows, etc. All windows run their programs completely independent of each other. Programs continue to run when their window is currently not visible and even when the whole screen session is detached from the users terminal.

daemontools is a collection of tools for managing UNIX services.

supervise monitors a service. It starts the service and restarts the service if it dies. Setting up a new service is easy: all supervise needs is a directory with a run script that runs the service.

multilog saves error messages to one or more logs. It optionally timestamps each line and, for each log, includes or excludes lines matching specified patterns. It automatically rotates logs to limit the amount of disk space used. If the disk fills up, it pauses and tries again, without losing any data.

A less encumbered version is available at http://smarden.org/runit/

DTrace is a comprehensive dynamic tracing facility that is built into the Solaris OS. DTrace can be used by administrators and developers, and can safely be used on live production systems. DTrace enables you to examine the behavior of user programs as well as the behavior of the operating system. Users of DTrace can create custom programs with the D scripting language. Custom programs provide the ability to dynamically instrument the system. Custom programs provide immediate, concise answers to specific questions about the behavior of particular applications.

Rsyslog is an enhanced multi-threaded syslogd supporting, among others, MySQL, syslog/tcp, RFC 3195, permitted sender lists, filtering on any message part, and fine grain output format control. It is quite compatible to stock sysklogd and can be used as a drop-in replacement. Its advanced features make it suitable for enterprise-class, encryption protected syslog relay chains while at the same time being very easy to setup for the novice user. An optional web interface - phpLogCon - can be used to visualize all data online.