If you have more than one computer running Ubuntu (or Debian), or maybe you are experimenting with different installations of Ubuntu using something like VirtualBox, you might find yourself using a lot of bandwidth and time when downloading packages from the Internet to update or add capabilities to your machine. By default each installation of Ubuntu will go directly to the Ubuntu download servers to get packages, producing a situation where you are downloading the same file multiple times through your connection to your ISP. There is an alternative to this situation though, you can download the packages through a host on your own network that will act as a cache. The next time any machine wanting that file requires it, the cache will serve its own copy, instead of having to download it again. This is a lot quicker, as the speed in your internal network will be much higher than the speed of the connection to your ISP, it is also a great bonus if you have maximum download allowances as part of your Internet connectivity package. Setting this up is not too difficult, thanks to a program called Apt-cacher.

Something we do have a wide choice of in Ubuntu Linux (and on many other Linux platforms) is virtualisation software. Previously in this blog I've covered VirtualBox, which was recently acquired by Sun Microsystems. A new version of this software is out, but unfortunately the download repositories have been disabled and the downloads moved to an old fashioned manual download and install model thanks to "U.S. export regulations". I hope Sun sort this out soon. Another option though has been quietly developing and as available in (K)Ubuntu 8.10. The Kernel-based Virtual Machine is an an open source option to run virtual machines on your computer which can benefit from hardware acceleration many many modern CPUs to achieve near-native speeds for the guest images. The user friendliness of this software has been greatly improved through the addition of Virt-Manager, a GUI front end for KVM which means that you don't have to use the command line anymore to set up, monitor and run your virtual machines. I took this software out for a test drive by making a virtual machine that can run Ubuntu 8.04 (32 bit) on my Kubuntu 8.04 (64 bit) system, you could of course also have Microsoft Windows as a guest, the software emulates an entire machine.

Asus have released a free SDK for their popular EEE PC. The SDK also includes a facilty to generate a VMWare image of an EEE from the support DVD supplied with the machine or with an image of that DVD. The SDK and an image of the support DVD can be downloaded from: http://sourceforge.net/project/showfiles.php?group_id=215613. As the Asus EEE PC uses the Linux operating system an SDK is not absolutely necessary for software development as everything you need could probably be obtained within your favourite distribution, so the emphasis in this SDK might be a little bit different to what you are used to. What Asus have supplied is a complete environment to create applications, so the SDK DVD is an installer disk for Xandros Open Circulation Edition (a free version of their product) which has the Eclipse IDE built into it, some tools for developing with Qt, and a Xandros produced package maker. So the idea is you can burn the image to a DVD and boot your computer with that and then you can get straight on with some development. You can also run the SDK in a virtual machine as well.

As with previous blog posts on the subject of virtualisation, I used VirtualBox to run an image of Windows Server 2008 Standard Edition(tm) on Kubuntu 7.10. You will need a fairly powerful machine with a lot of free hard disk space and free RAM. I set aside 15GB of hard disk space for the image and 1GB of RAM to be dedicated to the virtual machine.

You have probably already heard of the One Laptop Per Child Project, which aims to equip children in developing nations with low cost laptops to aid their education. The XO-1 is the first machine to be made by this project, and is very innovative in both hardware and software design. Getting your hands on one of these machines is quite difficult, especially if you don't live in North America, but what you can do is get hold of an image of the machine's operating system and run it inside a virtual machine.

Some time ago I got a free DVD set of Solaris 10 delivered to me. Solaris is a version of UNIX which is supplied by Sun Microsystems ususally with their servers, but more recently they have been supplying versions suitable for use on other equipment. I can't see it as a serious comptetitor to Linux but you might find this useful if you want to see what it is all about, particularly if you have servers at work using it.