I am a first-year high school English teacher, and I was looking to get computers in my room so I could have a writing lab. I was temporarily elated when our tech coordinator informed me via email that a dozen iMacs had been donated to the school and I was welcome to take a few for my room.
My excitement dissipated, however, when I learned the iMacs were built around the the turn of the century. 350mhz processors, 128MB or RAM, no firewire or USB 2. OS 9.2 — yuck. These computers couldn't even load cnn.com without flipping out.
So I started thinking. How can I make these computers functional again? While I had never really used a Linux distribution, I was quite familiar with the Linux philosophy. After a day of posting questions to ubuntuforums.com, I settled upon the distribution Xubuntu, which is stripped down OS built for older machines. I now have five previously dead machines resurrected and working again — navigating modern web sites and all.
Xubuntu comes with a host of applications perfect for the classroom, including fully functional graphics editing and word processing software. For my purposes though, I have my students writing in online word processors (Google Documents and wikis, mostly) to keep things simple. I've rearranged the desktops so the only apparent option is the Firefox icon. Once on the web, they are right at home.
I am totally satisfied with my Linux experience to this point. What these computers lack in power, they make up for in simplicity and ease of use. None has crashed, either. It seems to me that Linux is a viable solution for any educator with old, seemingly useless computers, and administrators shackled down by exorbitant licensing costs of running OS X or Windows on dozens or hundreds of machines ought to consider it as an alternative.
My question is: How can I make these systems even more powerful? What open source Linux software can you recommend that would augment my students' experiences?

