. If you give your subcontractor a bin file, then all they need is the Rabbit Field Utility . This is found in the Dynamic C Utilities folder. When you run the RFU, there is a Tab "File Locations". You will need to send your customer the RFU.exe, plus the coldload.bin, pilot.bin and flash.ini They will need to store these files in the same locations as shown in the file locations in the RFU. They will not have access to your source code since you will be sending a bin file.