elfdump generally dumps ELF contents in a low-level, raw format. It only handles a limited set of ELF notes though, omitting all others. It should display all ELF note data.
E.g.
% readelf -n /bin/ls Notes at offset 0x00000218 with length 0x00000030: Owner Data size Description FreeBSD 0x00000004 NT_FREEBSD_ABI_TAG FreeBSD 0x00000004 NT_FREEBSD_NOINIT_TAG % elfdump -n /bin/ls %
Also Solaris-style output isn't quite as expected -- e.g. from SmartOS (Illumos):
or for a core file