Just a passing thought, not sure if there is any mileage in it.
One solution to making DT downloads platform independent might be to consider emulation. Is it possible to find an "old" OS which could run a workable Music/Text version of the DT (using existing software) but can be emulated on more than one platform.
Something such as the old Commodore Amiga runs as emulations on Mac, Windows, Linux and other systems (possible copyright constraints on distributing a working emulation - needs a rom image). I believe that the Atari is also emulated for Linux, PC and Mac.
You would have a set-up which might be older technology, but all you would need to do when a new version of Windows or Mac-OS is released is wait a short while until a new version of the emulator comes out (and the people who programme these sort of things seem to be very keen and dedicated to getting their emulators running on the latest set-up).
Another development to watch out for is portable emulators which do not need to be installed on your computer. Not much available yet, but watch the link..... (a lot of applications have been added since I discovered the Portable Apps web site).

Quack!
GtD.