Recently there’s been a lot of news about OpenSolaris, more specifically in reference to the great progress made by virtualization technologies in it. In this article, I will exam some of these technologies, and compare them with the state of the art on other platforms.

Have you ever wanted to configure a personal firewall for your GNU/Linux box, but were scared of the complexity of iptables? Well, I might not be able to make you a security expert, but I can show you a tool that will help you to configure your personal firewall the easy way. The secret? Firewall Builder (also known as fwbuilder for short).

Did you know that it’s possible to build an entire telephony system centered around computers? One which is free of licensing costs too? Asterisk is a free software application written to do just that, and much more. Why? For the uninitiated, here’s why...

When my DVD player stopped working, I definitively proved to myself (and to people I know) that if there is a simple and effective solution to a problem and a complex one which promises unpredictable results, I always choose the second option. Instead of buying a new DVD/DivX/MP3 player for the modest price of $40-50, I decided to build a home-made device that would allow me to record the TV, receive podcasts, view webtv, play games, and a lot of other things that I considered cool. So my modest adventure with Freevo, GNU/Linux and a lot other free software begins...

This article is intended for new Linux users who wish to use their Linux-box for some real work. Speed control of an industrial motor? Sounds complicated? It’s not as complex an affair as it sounds. What’s interesting is that a PC powered with a Linux based Real-Time Operating System (RTOS) can be used to control anything from a small motor to a complex industrial drive with the utmost reliability. This article presents the implementation of a Digital PI (Proportional+Integral) Controller on a PC running RTAI (Real Time Application Interface). A system developed on Linux-2.4.24 kernel patched with RTAI-3.1 was used for the speed control of a 12V DC motor.

In the last article we parted ways after configuring a base FreeBSD system, enabling it with upgrades via cvsup and portsupgrade, and securing it with a simple ipfw2 firewall. The previous article created a solid foundation which this article will build on, covering the configuration of Postfix, amavisd-new, ClamAV, SpamAssassin, MySQL and finally SquirrelMail for web mail. The final setup will have all the bells and whistles of a high end-mail setup: web-mail, anti-virus filtering, spam filtering, and hosting unlimited domains with virtual domains and users stored in MySQL.

Security is a process, not a result. It is a process which is difficult to adopt under normal conditions; the problem is compounded when it spans several job descriptions. All the system level security in the world is rendered useless by insecure web-applications. The converse is also true—programming best practices, such as always verifying user input, are useless when the code is running on a server which hasn’t been properly hardened. Securing forward facing GNU/Linux web servers can seem like a daunting task, but it can be made much easier by breaking the process into manageable portions.

“Do you pine for the nice days of Minix-1.1, when men were men and wrote their own device drivers?” Linus Torvalds

Pre-requisites

In order to develop Linux device drivers, it is necessary to have an understanding of the following:

Everyone likes pretty pictures. The newsagent’s stand is now crowded with glossy magazines, roadside advertisements glare out at you as you drive along the freeway, you see a wondrous mosaic as you look at all the packaging on supermarket shelves. Television long ago replaced the radio as standard home entertainment and the fact that you cannot judge a book by its cover doesn’t prevent the vast majority of the human population from doing so. The same applies to computers now. The GUI (Graphical User Interface) or “windows functionality” has become part of the machine that everyone now takes for granted.

We have written this manifesto always wishing to unfold the concept and practice of free/libre and open-source. We wanted it to stretch out so that it might take us in new directions. To start off with, we were sure that the practice of non-proprietary software code production was not a narrowly technical or economic affair, but something that was always also socio-political. [...]

One comment: No wireless. Less space than a nomad. Lame.

Rob “CmdrTaco” Malda introduced the iPod to the Slashdot crowd with a statement rivalled only by Bill Gates’ quip “640 KB should be enough for anybody”.

Since that post in 2001, Apple’s iPod quickly became one of the most successful products in consumer electronics history. While its success largely derives from its “hip” factor and stylish design, the iPod’s integration with the iTunes music application and the iTunes Music Store has made the device a favorite among music listeners.

Dspam filters spam with the best. In my installation, it stops over 98% of all spam: I’ve only had one false positive in the last year, and that was a message to the Dspam list that contained a real spam!

Administering Dspam is a breeze. No rules to configure, new users can automatically benefit from a global dictionary and quarantine management is simple. But getting a Dspam quarantine set up the first time, without losing any email, can challenge the most seasoned mail administrators.

If you are responsible for maintaining an internet-connected mail-server, then you have, no doubt, come to hate spam and the waste of resources which comes with it. When I first decided to lock down my own mail-server, I found many resources that helped in dealing with these unwanted messages. Each of them contained a trick or two, however very few of them were presented in the context of running a real server, and none of them demonstrated an entire filtering framework. [...]

In a few years viewing source code within the major components of software infrastructure will probably be a routine way of doing business. In the meantime it seems that the only reason managers want free software is because it is free (as in free of costs). That’s not a good reason in itself: in the long run there are compelling reasons that robust, mission critical infrastructure software should be made free software.