For its part, musl libc (Alpine's libc) makes minimal use of /proc, and only when necessary. The only unconditional uses I see are for pthread_getname_np/pthrea

For its part, musl libc (Alpine's libc) makes minimal use of /proc, and only when necessary. The only unconditional uses I see are for pthread_getname_np/pthread_setname_np, ttyname_r, and some dynamic linking reflection bits. But as shown in the article, FreeBSD also has the linprocfs filesystem, which emulates a subset of Linux /proc: https://man.freebsd.org/cgi/man.cgi?query=linprocfs https://man.freebsd.org/cgi/man.cgi?query=linprocfs