Darwin also uses heirarchical namespaces by default; On Linux you can do this to a limited extent with dlmopen() but not as much as you may want (e.g., to link

Darwin also uses heirarchical namespaces by default; On Linux you can do this to a limited extent with dlmopen() but not as much as you may want (e.g., to link in a library linked to another libc -- but this is unique to Linux, most platforms only have the single libc)