Some people use emulators to emulate current hardware or even hardware similar to their own to allow the to test on different platforms without the need for more hardware or rebooting.

Some examples are:

Here is a huge list of all types of emulators that will run on Linux. You should be able to find whatever your looking for here.

Now we'll have a look at qemu. We just execute the following command. 

qemu -net user -cdrom /share/dsl-2.3.iso -boot d