Greg Kroah-Hartmann, one of the Linux Kernel devs, gives an interesting Q&A to Google about Linux Kernel Development. Very interesting to see the rate of development particularly, and the KVM virtualisation.

For those that don't know, the "Kernel" is the piece of Linux that is at the core. It is the part that interfaces directly with your hardware, and so works with "drivers" in order to do so.

In order to find out what version of Kernel you are running type this in terminal:

uname -r

A result:

2.6.24-19-generic

means that it is a kernel of base 2.6, version 24, subversion 19, for generic use.

It is possible to make your own Kernel (but a lot of work), or use other Kernels specifically to support a certain piece of hardware. Very newly released hardware often has an issue where this needs to be done. So, if you are planning a new machine, go for the six-month old technology at least (with modern up-to-date Linux distribution) unless you are adventurous.