Info-ZIP

Zip 2.31

Zip is a compression and file packaging/archive utility. Although highly compatible both with PKWARE's PKZIP and PKUNZIP utilities for MS-DOS and with Info-ZIP's own UnZip, our primary objectives have been portability and other-than-MSDOS functionality. Features not found in the PKWARE version include:

Plus it's free, as is the source code. Whoa.

Zip is useful for packaging a set of files for distribution, for archiving files, and for saving disk space by temporarily compressing unused files or directories. Zip puts one or more compressed files into a single ZIP archive, along with information about the files (name, path, date, time of last modification, protection, and check information to verify file integrity). An entire directory structure can be packed into a ZIP archive with a single command.

Zip has one compression method (deflation) and can also store files without compression. Zip automatically chooses the better of the two for each file. Compression ratios of 2:1 to 3:1 are common for text files.

All known vulnerabilities are fixed in Zip 2.31. (Let's hope it stays that way.)

Zip 2.3 and (presumably) all previous versions have a buffer-overrun vulnerability relating to deep directory paths that could potentially lead to local privilege escalation (e.g., in the case of automated, Zip-based backups). See the FAQ page for details.

Contents of This Page:

Latest Release

New features in Zip 2.31, released 11 March 2005:

Future Plans

The next major release of Zip will be version 3.0, with multi-part archive support--something we've been begged to implement for years (and something that we would have, had we not been interrupted by numerous other eventful things). It is expected also to have large file support and support for 64 KB deflate, although the actual feature list is still in flux. Zip 3.0 should be released sometime in 2005, possibly as early as summer, and hopefully together with a corresponding UnZip release.

Ready-to-Run Binaries

NOTE: If you find a broken link, please tell us about it. Thanks!

Ready-to-run binary versions of Zip are available for numerous platforms and operating systems. Unix binaries are generally provided only if the platform does not come with a bundled C compiler by default. Most older Unix systems do; please grab the sources and compile your own!

AIX
IBM AIX 3.2.5 binaries (compatible with AIX 3.x through 5L) and AIX 4.3 binaries (compatible with AIX 4.3 and all AIX 5L versions) can be found at:

Amiga
AmigaDOS binaries can be found at most Aminet mirrors and at the Info-ZIP mirror sites:

AOS/VS
Coming soon? [currently in beta, sort of]

Atari
Atari TOS/MiNT binaries can be found at:

BeOS
BeOS binaries (for x86 or PowerPC systems) can be found at:

CLIX
Intergraph CLIX binaries can be found at:

Convex
ConvexOS binaries can be found at:

Digital Unix (OSF/1) / Ultrix
Digital Unix binaries for Alpha AXP and Ultrix binaries for MIPS can be found at:

FreeBSD
FreeBSD binaries for x86-32 and x86-64 can be found at:

HP/UX / MPE/iX
Hewlett-Packard HP-UX (PA-RISC) and MPE/iX (HP 3000) binaries can be found at: Thanks to Richard Lloyd for providing the HP-UX binaries and to Jens von Bulow for providing the MPE/iX binaries!

Human68K (X68000)
Human68K (X68000 hardware) binaries can be found at:

Linux
Linux binaries for Intel x86 hardware can be found at: Note that the Zip sources should compile trivially on any Linux platform.

Macintosh
A fully up-to-date graphical Mac OS port (MacZip, both Zip and UnZip functions) can be found at: In addition, a command-line version for Mac OS X only (from Apple's Developer Tools) is available courtesy of Roger Jolly.

MS-DOS / PC-DOS / DR-DOS
DOS binaries can be found at:

MVS / OS/390 OpenEdition
Binaries for both classic MVS (a.k.a. OS/390 Base) and OS/390 OpenEdition can be found at: Note that we no longer have any mainframe folks among the core developers, so if you have problems or questions, try the mailing list(s), not the bug form. We cannot help you. This port is officially unsupported.

NetBSD
NetBSD binaries for many platforms can be found at:

Novell Netware
We may have official executables someday, but in the meantime, beta executables (may be buggy and/or hard to install) are available here. Also see the related HrZip and HrUnZip NLMs, which may (or may not) include more features.

OS/2
1997 OS/2 e-Zine! Readers' Choice Winner OS/2 binaries can be found at:

QDOS / SMSQ
SMS/QDOS binaries can be found at:

QNX
QNX binaries can be found at:

RISC OS
RISC OS binaries (e.g., for Acorn Archimedes) can be found at:

SCO Unix
SCO Unix binaries can be found at:

SGI Irix
SGI Irix binaries (compatible with Irix 4.x through 6.x) can be found at: Also see http://freeware.sgi.com/ for SGI-packaged versions (possibly slightly out of date).

Solaris / SunOS
Sun binaries (either Solaris 2.x or SunOS 4.1.x, on either SPARC or Intel x86) can be found at:

Tandem NSK
Tandem NSK D30 binaries (should also run OK on D20 and D40) can be found at: Thanks to Dave Smith for doing the port and providing the binaries! (Also see his Info-ZIP for Tandem web page.)

VM/CMS
VM/CMS binaries can be found at: Thanks to Greg Hartwig for some final code tweaks and for providing the binaries! Note that we no longer have any mainframe folks among the core developers, so if you have problems or questions, try the mailing list(s), not the bug form. We cannot help you. This port is officially unsupported.

VMS
VMS binaries for VAX and Alpha/AXP processors can be found at:

Windows 3.x
A graphical Windows 3.x port (WiZ 4.01, with both Zip and UnZip functions) and a 16-bit Windows DLL can be found at:

Windows 9x / ME / NT / 2000 / XP / etc.
Windows NT/2k (mainly for IA32/x86, but also IA64, x86-64/EM64T, Alpha AXP, MIPS and PowerPC) and Windows 95/98/ME/XP binaries -- including both graphical (WiZ) and command-line flavors, plus a 32-bit Windows DLL -- can be found at: See also CInfoZip and CGZipLibrary in the Related Links section for VB and MFC wrappers to the DLLs.

Source Code

Info-ZIP's portable C source code for Zip, UnZip, WiZ and MacZip (including encryption code) is freely available from:

Note that version 1.0 of the encryption/decryption code is available only from the Netherlands site and works only with Zip 1.1. Version 2.9 works with Zip 2.3 and will be incorporated into the main Zip 3.0 source archive, as is already the case with UnZip 5.51 and later. (Note also that the HP/UX compiler breaks Zip's encryption if optimization is turned on--or did so several years ago, at any rate; to work around this, compile the encryption code with optimization disabled, or else use GNU C.)

Other Stuff

Technical information on zipfiles and other assorted Info-ZIP documentation is available from:

Technical information and documentation for deflate/inflate and zlib are available from :

Further information on where to find Info-ZIP stuff, including some BBSes and commercial online services, is available in:

Information about commercial use, modification and redistribution of Zip, UnZip, WiZ and MacZip is available in:

It's basically BSD-like, but note that there may still be a few remaining files in some of the packages that are covered by different licenses.

[Info-ZIP] Return to the Info-ZIP Home Page.

Last updated 8 September 2005. Web page maintained by Greg Roelofs. Please direct Info-ZIP queries (availability, ports, bugs, etc.) to Zip-Bug .
Copyright © 1995-2005 Greg Roelofs.
Zip is maintained by Ed Gordon. 		Primary ftp site hosted by LEO.