A number of users run gCADPlus under Linux. The most common distribution used is Ubuntu. Here are some set up notes from DW who uses gCADPlus under Ubuntu. Many thanks for permission to publish this.

"I've just tested the 5.9 release under Wine. Everything worked fine

except the old standing problem that Help > Contents would simply open
the "Wine Explorer" but not display the actual help file.

Now this bothered me and I had a deeper look into it. I found the
solution via https://www.winehq.org/pipermail/wine-bugs/2013-January/346474.html

Basically Wine Explorer does not like paths with "()" in them. Now if
you have a 64bit machine and do a standard wine bottle install you end
up having gCADplus installed under

c:\Program Files (x86)\gCADplus

Solution: Always install the (32bit) gCADplus program in a 32bit wine
bottle and you will get the installation location:

c:\Program Files\gCADplus
i.e., no "()". Now the help browser works as expected and there might
also have been other parts been failing that I just haven't noticed
before.

Here my installation steps (all one line):

$ WINEARCH=win32 WINEPREFIX=~/.local/share/wineprefixes/gcadplus/ wine
gCADPlusMetricSetup.exe

Now the help browser works again Note that the help browser seems to have a problem displaying the actual content (probably gecko related) when using the stable 1.6.x versions of Wine. So better always using the latest from the 1.7.x 

series."

gCADPlus under Linux