Nothing; it is just much smaller by not providing POSIX and Linux like interfaces. Alpine proves full musl can already run a full distro's worth of programs an

Nothing; it is just much smaller by not providing POSIX and Linux like interfaces. Alpine proves full musl can already run a full distro's worth of programs and is very easy to port anything using glibc. Newlib tends to be used in projects like Cygwin as a small C standard library, where the rest of the POSIX API is implemented separately (by proxying to Win32 system calls for Cygwin).