Hi,
I have used EMC for a couple of years now and have recently upgraded to EMC version 2. It is available free from www.linuxcnc.com and is very flexible and easy to interface, many types of interface are supported and the support you get from the live forum is very good. It can be configured for anything from 1 axis upto 6 and understands about joint kinematics ( angular joints on machining head ) it can also run a hexapod machining platform.
David
( never stop learning )
http://www.steamcastings.co.uk/