Implement the Tunes project On Top Of POSIX, so that Tunes runs on any new hardware, as POSIX is the one standard, which is ported on any new architecture (actually, most new architectures are conceived with POSIX in mind).
Thus, as new hardware platforms grow in power, even if O'TOP offers only a constant 10% of efficiency as compared to "optimized C", it will allow TUNES to follow hardware enhancements, and may be a platform to develop architecture-specific implementations. Moreover, architecture-specific enhancements to the POSIX implementation, even if slower and less reliable than a full port, may provide more speed and much more functionality than standard POSIX optimized C.
The implementation should be faithful to the LLL specifications, and device drivers should be provided to allow basic memory management, human interaction, and access to mass storage.