Linux will run on older hardware, but it can not overcome hardware
limitations. I have to make this point because new users often have the
misconception that Linux will have their 5 year old machine to
performing like a new machine.

Linux/Ubuntu is certainly better than running XP on an older machine for
security reasons alone. Yes, there are plenty of free applications that
make it more useful on an older machine than Windows. What new users
have to keep in mind is that Linux/Ubuntu can not run faster than a
machine's hardware will allow.

As with Windows, in Linux/Ubuntu the larger an application is, the
slower that it will run on older machines. While e-mail and web surfing
can be done on older machines, the ability to utilize streaming video,
photo editing (Gimp) and using OpenOffice gets more limited with the age
of a machine.

I've put Linux/Ubuntu/AntiX on 10 year old machines. They work, but
they are less functional than a netbook.

I'm only saying this to keep new users' expectations within the realm of
reality.