An old one I read on the linuxquestions forum
What if toasters had Operating Systems?
a) Windows toaster:
The windows toaster looks nice, but sometimes it just won't make toast, it
either comes out burnt or raw, or it stops half way through. also, you
have to unplug the toaster, plug it back in again, and wait 5 minutes each
time you want to try and make some toast. For every loaf of bread you buy,
you are forced to buy a license for a new toaster to go with it, and you will
get sued if you let someone else have some of your toast.
b) MAC toaster
The MAC toaster has no settings or controls and it looks very stylish, but
will only accept proprietary size bread which can only be bought from
Apple main dealers at 10 times the price of regular bread. If it breaks
you will have to ship it to a licensed repair shop for service. The toast is
fine except that the size of the bread is so odd, you can't actually eat
the toast it produces, although it does look good.
c) Linux toaster.
The linux toaster looks awful, it has wires crimped together hanging out
of it, and pieces grafted from other toasters. the first time you make
toast with it it burns it, the next time its raw, but after you read the
man pages and invoke the command line, toast -verbose -breadsize 50132
-eject -o z3321 > /dev/toast | more, and it makes perfect toast forever
and never breaks.