Have you looked at the Apple ][ emulator programs that run under Linux,
as well as the commercial Mac emulator Executor which has a demo
version for Linux? These programs have some support for the Apple file
systems.
You're not planning any support for floppies are you? As far as I know
the Apple ][ and older Mac floppies cannot be read on a PC floppy
drive. When I moved files from my Apple //e to PC I used a 300bps modem
because the Apple lacked a serial card :-(