Complex sentence: The reasons for Rosetta's lesser capabilities as compared with Apple's earlier 68k emulator for PPCs lie within its implementation-Rosetta is merely a userland program that can only intercept and emulate userland code while the older emulator was located at a much lower level.
Split into simpler sentences: The reasons for Rosetta's lesser capabilities as compared with Apple's earlier 68k emulator for PPCs lie within its implementation. While Rosetta is merely a userland program that can only intercept and emulate userland code, the older emulator was located at a much lower level.