EMC

Well EMC provides:
A graphical user interface (actually several interfaces to chose from).
An interpreter for "G-code " (the RS-274 machine tool programming language)
A realtime motion planning system with look-ahead.

Operation of low-level machine electronics such as sensors and motor drives.
An easy to use "breadboard" layer for quickly creating a unique configuration for your machine.
A software PLC programmable with ladder diagrams.
Easy installation with. Deb packages or a Live-CD.