There should be very little overlap between X3J11 and POSIX. If there is, then at least one of these bodies should reconsider its purposes to remove that. Some small degree of overlap might be impossible to avoid, but it should certainly be minimized. X3J11 are standardising the C languale (or creating a new one, depending on your point of view). POSIX are standardising the operating system interface. These are two different functions.. an X3J11 C implementation should be able to be made on VMS, VM/CMS, PRIMEOS, ... thus X3J11 cannot possibly set about standardising the operating system interface, only the C programmers (higher level) functions. Thus they can standardise fopen, but not open. POSIX (P1003.1) on the other hand should enable the programmer to work in C, Pascal, Ada, PL/I, Fortran, Modula, Occam, Prolog, ... What's important is the capabilities of the system (the file system, time keeping, signals, etc). These things don't depend on the language, regardless of their effects being expresed in (some random dialect of) the C language at the present time. kre ps: this discussion really belongs in comp.std.unix, not elsie!tz, perhaps someone should forward it there?