Hi Alan,
I'm pretty sure that EMC2 (Linux OS) supports standard G and M Codes so you should be able to use the GCode postprocessors in VCarve Pro.
You can test this using the Trial version of the software, opening one of the Evaluation files and Saving the Toolpaths using the GCode postp's. If you have any further questions drop a note to
support@vectric.com.
I'd be very interested to know whether this works for you.
Tony