Self-modifying homoiconic expression written in the Julia Language.

selfmodifying.jl

ex = quote
  s = string(ex)
	o = s	
	array = uint8(collect(s))
	for i = 1:length(array), bit = 0:7
	  if rand() < 1/(length(array)*8)
	    array[i] $= (0x01 << bit)
	  end
	end
	s = bytestring(array)
	try:
		ex = parse(s)
		eval(ex)
	catch:
		ex = parse(o)
		eval(ex)
	end
end
eval(ex)