Hi all not new to cnc or building cnc machines but don't have not a clue about Linux
I was at a show recently and spoke to a guy who had converted a lathe and was using Linux cnc as this is my next project which i already have the parts for. So I am thinking of using Linux cnc
I have an older Sony laptop with a parallel port which I plan to use as my other machines all use network cables
Go to LinuxCNC . I went through the same process as you. I am not a Windows fan, but for work I am forced to use it. Supporting Linux and Windows both was too stressful. I gave up, bought a board with a USB interface and now have a system that supports whatever Windows system is around and Mach3 with no hassles. (best is that I do not really have to have a dedicated machine just for the Mill but can if I want) Yes I was able to get Linux CNC going. There are instruction files on that web site. Just be sure before you start that you really want to support yet another operating system. For setup you need exactly the same information that you have in Mach3, but Mach3 just seemed easier to me. In the end it is all about having a stable running machine, and you can get there many different ways. Best of luck.
Tholling55