1. A system for compiling versions of a file in a first and second programming language into a merged output file in the a second language in a computer system comprising: means for modifying an original file in the first programming language to create a derivative file in the first programming language; means for translating the original and derivative files in the first language into original and derivative output files in the second language in a computer memory; means for modifying and storing the original output file in the second language in the computer memory according to user input to create a modified original output. file,; and means for interleaving code segments from the modified original and derivative output files and storing the interleaved code segments as the merged output file in the computer memory so that code segments from each of the modified original and derivative output files which correspond to each function name are stored together.