stdio - 1990-1991 Steve Summit reimplementated stdio, user-definable underlying I/O functions, improved error handling, new routines for "string" I/O, and efficient unbuffered I/O sfio - 1991-1998 David Korn and Kiem-Phong Vo, All rights reserved." beherscht alle features, schwaches layering, portable, fast sio - 1993 Panos Tsirigotis kein socket support aber mmap bstdio - 1993-1994 Chris Provenzano threadsafe stdio based on the BSD stdio, uses pthreads buff - 1995-1999 Robert S Thau, Apache Group Apache Buffer and I/O library substdio - Dan Berstein - minimalistic stdio bio - 199x-1999 Eric A. Young BIO, sockets, memory, stacking rt-aio - 1997 Ulrich Drepper pthread basierte Async IO von glibc