When 5 axis motion is in question, I think he is asking five axis tool comp eg. "Rotation Tool Center Point" ??
Answer is mach do not have this feature, but it do not mean mach can not handle 5 axis machining!
I use 5 axis toolpaths made so that tool lenght is handled by postprosessor. Post is more complex and also quite expensive but so is 5 axis CAM...
-Mika