Grbl fork for the Carvey machine
You can compile and flash a Carvey using the Arduino IDE. You just have to put this repo into the libraries folder (by default ~/Documents/Arduino/libraries) or symlink this directory there.
Then re-open the Arduino IDE and look under Examples -> gCarvin -> grblUpload. That sketch will compile and upload the firmware.
Make sure to have the "Board" type set as "Arduino Mega 2560".