You must be joking, right? Bitcoin is open-source, anyone can modify the source code at will.
As reference, go to the Alternate Cryptocurrencies sub-forum
https://bitcointalk.org/index.php?board=67.0.
There you will meet Worldcoin,Powercoin,Feathercoin,Hazardcoin,Sexcoin and about 40+ more coins.
Here is another list of different coins
http://coinchoose.com/P.S
If you think that programs are created by just renaming a file, you really have no business with this sort of occupation.