Like most Manufacturers Motorola also has begun to allow user to unlock bootloaders of their devices. Unlocking a bootloader can allow the user to Install custom ROMs as well as Custom Kernels. Unlocking bootloader is not for the faint hearted. If not performed properly it call potentially harm your device. However, if you follow the steps perfectly no harm will be caused. Please note that Unlocking your Device will void your Warranty!
Note: This process will erase all data on your phone. However, the data in SD card will remain safe.