A Slimline Debian Install: It's Easier Than You Might Think
There are some superb desktop Linux distributions that are designed to work with very old hardware. For example, Puppy Linux is a great choice to quickly turn an old PC into a secure, easy to use word processing, email and light web browsing workstation. Puppy can work minor miracles on very old hardware, and I carry a Puppy boot CD-ROM around with me as my emergency recovery system.
However, there are a lot of machines floating around that are a bit too good for something as limited as Puppy, yet not powerful enough to run one of the major distributions. I'm taking about machines with maybe 256MB-512MB of memory and a CPU around the 600MHz mark. My new thing in these situations is to deploy the latest Debian in a slimmed down form. The advantage is that you end up with a completely up to date Linux distribution and it's still standard Debian underneath it all. As it's a real Debian install, it gives you security along with something that can be upgraded with standard software. It's a great project if, for example, you've got a structurally sound old laptop that you fancy giving away to a relative.
It's pretty simple stuff really, all you need is an old machine and a working Internet connection. You can start with the Debian netinstall disk (for a PC, you need the i386 image at about 150megs). Once you've burned the ISO, boot from the disk and begin the install, proceeding as normal until you reach the package selection screen. Here, deselect "desktop workstation" and continue while the installer does its stuff.
Pay attention here, you need to tell it not to install the desktop environment.
After completion of the install and a reboot, you should have a complete Linux distribution with a command line, network support and some basic admin tools. For cowards like myself, the most important tool is Aptitude, a textmode package installer that looks like an old DOS utility (anyone who calls me Grandad for remembering DOS gets a slap). Hit Ctrl-T to bring down the menu and then use the cursors to navigate to the search option. You can then use the rather old-fashioned interface to search for packages and select them for installation. I'd recommend the XFCE desktop environment, the Firefox web browser (called Iceweasel in Debian-speak), the ALSA sound system, AbiWord processor and the XDM login manager. Select install, wait a while and reboot again. Voilà, a complete, customized, light-weight setup that should simply fly on older hardware.
A simple but functional desktop that consists of everything that most people need.