Contents of the OS2 sub-archive for UnZip 5.0 and later:

  Contents      this file
  makefile.os2  makefile for MSC, IBM C Set/2, gcc/emx, or Watcom C/386 9.0
  os2unzip.c    OS/2 HPFS/FAT support routines
  unzip.def     OS/2 linker definition file
  zipinfo.def   OS/2 linker definition file

There is, as yet, no support for the Zortech or gcc2.1 (Michael Johnson port)
compilers, and the Borland 32-bit OS/2 compiler doesn't exist yet.