The employees who do the actual work in IT need all the help they can get; these open source tools are handier than most.
RANCID: Short on configuration, long on resources
RANCID is one of those tools that you'll set up once, make very minor modifications to over the years, and praise for saving your bacon in an emergency. RANCID performs a very simple function: retrieve and organise the configurations of network routers, switches, and firewalls. When set to run every hour, for example, RANCID will email admins when changes are made to any monitored piece of gear, and add the configuration to a version control database that you can then run diffs on to see exactly what changed and when. In the event of a catastrophic failure of a router or switch, you can pull the configuration back quickly and easily, and be sure that it's the latest possible copy.
There are very few utilities that require so little configuration yet can provide such an immense resource during outages, but RANCID is certainly one of them.
MediaWiki: Internal documentation made easy
If you don't have an IT wiki running in your organisation, you should start one now - right now. Internal documentation has never been so easy, and MediaWiki is a fantastic package to drive this initiative.
MediaWiki is the code behind Wikipedia and millions of other wikis. It's easy to set up and run, and it can completely transform the documentation tasks of any IT organisation. In many cases, documentation on applications, hardware, and network equipment can not only include information on the component, but also have direct links to management interfaces, administration panels, and so forth. Rather than typing a URL into a Word document that's printed out and stored in a three-ring binder (nobody does this anymore, right? Right?), you can simply embed those links inline in the wiki page for that element. You can even include photos, diagrams, and more.
CentOS: Red Hat Enterprise Linux, open source style
One common characteristic of all the above projects is that they run on Linux. Some also run on Windows, but they all are quite at home with Linux. In keeping with the open source flavour, you can easily run all of them on CentOS, which is essentially the open source version of Red Hat Enterprise Linux.
There's no licencing, no cost, and no support, but for boxes that run these tools, that may not be an issue. In fact, a single CentOS virtual or physical server can run all the above tools for a sizable IT shop without breaking a sweat. In environments where mission-critical Linux boxes must run licenced and supported version of Linux, CentOS can find a home in lab environments or for ancillary tasks. Go forth and download. Then give something back and donate a few bucks to the project.
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