Someone can tell me which is the best software for laser engraver machine?
The best is the one that works like you need/expect it to. For the K40 machines there is free software that works with them as they are. There is laserweb. I think chilipeppr will drive a laser. Both Mach3/4 and LinuxCNC will drive a laser if you know what you are doing.
I use LaserWeb4, GrBL and smoothie compatible with untested marlinkimbra
Creio que os software que trabalham com Arduino, os mesmos que gerenciam impressoras 3D, digo isso porque uso os mesmos em um projeto de corte laser, são pequenos e simples. Boa sorte