I've recently started playing around more with the source of Grbl, the motion control software that powers the Shapeoko CNC. It was simple enough to get into and start tweaking, but uploading the new firmware to the Arduino was a pain. On Windows platforms, there is a program called XLoader that makes it simple to upload the compiled "grbl.hex" file to the Arduino. But there wasn't a similar GUI for Mac. So I made one. It is a pretty bare-bones wrapper around the command line tool avrdude; it adds serial port connection help and automatic baud rate setting depending on the chosen type of Arduino.