http://dank.bengler.no/-/page/show/5471_gettinggrbl

https://github.com/simen/grbl

ShapeOko Grbl settings calculator

Z Axis Mod for Shapeoko

http://opensourceecology.org/wiki/GRBL_Config   How to Modify GRBL Settings

GRBL Arduino Library – Use the Arduino IDE to flash GRBL directly to your Arduino: http://blog.protoneer.co.nz/grbl-arduino-library/

https://github.com/damellis/gctrl   gctrl: a simple GUI for GRBL

https://www.synthetos.com/webstore/index.php/assembled-electronics/grblshield-grbl-arduino-diy-cnc-shield.html

https://github.com/timkrins/grblfeedr GUI to feed G-code to the GRBL

http://grbl.tumblr.com/





Here you can find a GRBL fork for Printrboard and Teensylu:
http://blog.lincomatic.com/?p=564
https://github.com/lincomatic/grbl