The Free On-line Dictionary of Computing (18 March 2015):
A file compression and archiver utility for MS-DOS
and Microsoft Windows from PKWARE, Inc.. PKZIP uses a
variation on the sliding window compression algorithm. It
comes with pkunzip and pklite and is available as
shareware from most FTP archives in a self-expanding
Current versions as of 1999-10-07: PKZIP 2.60 GUI for
Microsoft Windows 3.1x, Windows 9x, Windows NT; PKZIP
2.50 Command Line for Windows 9x NT; PKZIP 2.04g for MS-DOS;
PKZIP 2.51 for Unix, (Linux, SPARC Solaris, Digital,
HP-UX, IBM AIX and SCO Unix); PKZIP 2.50 for OS/2;
PKZIP for Open VMS/VAX.
WINZIP is a version with a GUI for Microsoft Windows.
A distribution in about 1995-06-22 claiming to be "PKZIP 3"
was actually a Trojan horse which attempted to reformat the
hard disk and delete all files on it.
[Status, history of WINZIP, PKLITE?]