Presentation of new web based CAD software which would simplify work with desktop CNC machines like Shapeoko. It is still in beta and the website takes mailing list notifications sign-up.
http://www.easelcnc.com/ (domain not working anymore)
new Easel homepage:
http://www.easel.com/
Here is Easel by Inventables:
Overview of easel interface:
Update:
Here is a tutorial on how to use Easel with raspberry Pi:
http://diy3dprinting.blogspot.com/2014/11/how-to-run-easel-cad-on-raspberry-pi.html