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 2.32. (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.|
New features in Zip 3.0, released 7 July 2008:
The next major release of Zip will be version 3.1, with AES encryption, complete Unicode-comments support, extended attributes, and perhaps some other things.
NEW RELEASE: Most binaries are contributed by third parties, so there's no fixed schedule for when any of them might appear. Those binaries typically provided by Info-ZIP team members (DOS, Win32, OS/2, Linux, FreeBSD, VMS) have already started showing up and should be fully available within a few weeks, though we make no promises. Please be patient, and feel free to grab the sources and compile your own! (Yes, even you. Free, downloadable compilers exist for all major OSes!)
Ready-to-run binary versions of Zip are available for numerous platforms and operating systems, but for most systems, only older binaries are available. The three primary CTAN sites (and their many mirrors) contain a snapshot of these binaries, current as of roughly 2004 (i.e., UnZip 5.51 and Zip 2.3 timeframe):
Here's a quick guide to the directory structure of the old ftp site:
As of 2007, the latest sources and binaries for Zip, UnZip, WiZ and MacZip (including encryption code) are available only at Info-ZIP's SourceForge site.
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 (possibly) find Info-ZIP stuff 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.
Return to the Info-ZIP Home Page.
Copyright © 1995-2008
Zip is maintained by Ed Gordon.