For those who aren’t aware, Knoppix is a bootable live system distribution of Linux. In other words, a Knoppix Live CD or DVD allows you to run a distribution of Linux without having to install any software on your machine. While Knoppix isn’t the only distribution that runs live, it’s one of the more popular distros and ideal for education. Here are many other live distros.
And there’s plenty of open source software included with Knoppix.
Due to on-the-fly decompression, the CD can have up to 2 GB of executable software installed on it (over 8GB on the DVD “Maxi” edition).
If you are interested in giving Linux a try, or at least seeing what all the hype is about, this is a great place to start.