Developer website: Aelius Productions
Every time Mac OS X starts up it recreates the 'mach' and 'mach.sym' files and they become visible next time you boot Mac OS 9. MacMachBegone! is a very simple program which makes them (and a couple more) invisible so that they don't clutter up the hard disk. It is very fast (you hardly notice it launch) and has a very small file size.
MacOS 9.0 or later