
You can even set up web server with Content Management System (CMS), such as Joomla! So, here is brief report how I did that. First you will need to set up some modern operating system. My choice is Debian, but probably any of available Linux base systems will do, so you can choose your favorite distribution. Since installation of Debian is thoroughly covered at their web page, I will not go into detail here. I will just briefly report that I have managed to install Debian version 4 (etch) - base system from 1.4” floppy disks (you will need three of them, if you decide to follow that way). After installing base system, first package that I have installed is OpenSSH (#apt-get install ssh - This command will install the OpenSSH server and client.), so I could access it from the other machine.
Apache web server and all the other prerequisites could be installed in a similar manner, but before you do so, it is advisable to check which versions will work with your Joomla package. You can find installation instructions and which versions of PHP, Apache, and MySQL you need, here.

Then you can proceed in the similar manner:
#apt-get install apache2
#apt-get install libapache2-mod-php5
#apt-get install mysql-server
#apt-get install php5-mysql
There is also Joomla package for Debain, but apt-get installation did not work for me. So, I was following instructions available at Joomla web page.
These are quite simple. Just download and unpack Joomla package in the www directory. In most cases that would be /var/www and follow the instructions. If you get into trouble just google it. It is very likely that your issue have been already resolved. After putting some content on your site, you might want to share that with the world. If your box has a dynamic IP you have several choices for your net presence domain. Check no-ip and dyndns. It is also important to have your local IP address (home network IP) and port properly forwarded through your firewall. If everything is set up correctly, it should work!
Update: I have upgraded my Debian to version 5 (lenny). I did network setup since there is no support for floppy installation anymore. It took very long to install only the base system, so be patient and have something to keep you busy while you waiting. I have also updated Joomla to the most recent version, and I am happy to report that it works with the most recent versions, on the old dusty Pentium MMX machine.