Handling big FP numbers

[Murilo via Digitalmars-d-learn]

Why is it that in C when I attribute the number 
99999912343000007654329925.7865 to a double it prints 
99999912342999999470108672.0000 and in D it prints 
99999912342999999000000000.0000 ? Apparently both languages cause 
a certain loss of precision(which is part of converting the 
decimal system into the binary system) but why is it that the 
results are different?