Not Mach4, it's wank and is "developed" by the numpties who buggered the last 3 releases of Mach3!
Linux CNC has inadequate support and disorganised development by non-machinists and shambolic hobby machinists - if you want to learn to set up linux and configure and use something which will still need a PC fill yer boots.
Centroid still requires a Windows PC so you have to pay for it and Windows!