User:Closeapple/info/Comparison of ZIP file archiver support

Archivers in the chart are chosen primarily by how widespread they have been; the chart can be used to get an idea of what features of ZIP files can be expected to be generally available. It is not intended to be a "me-too" list for every archiver available.

Version notes

 * 7-Zip:
 * , 15.12 was the current stable version, and has had the same compression support since 15.05 beta.
 * Info-ZIP:
 * Info-ZIP's Zip 1.1 was the last version to support creating Shrinking and Imploding, and is probably therefore the last easily-available program to do so.
 * , Info-ZIP's Zip 2.32 and UnZip 5.52 were the most widespread versions on most Linux distributions. Zip 2.32's man page explicitly says it supports only store (method 0) and deflate (method 8).  Some binary distributions of UnZip 5.52 have USE_UNSHRINK (method 1) and USE_DEFLATE64 (method 9).
 * Info-Zip's Zip 3.0 and UnZip 6.0 are the newest, but not as widespread yet. Both Zip 3.0 and UnZip 6.0 mention bzip2 (method 12) support in their new features lists.
 * PKZIP:
 * 2.04g was the classic version used in DOS for years, and is the reason for method 8 becoming the practical baseline standard for ZIP support.
 * 2.50 was the last version for MS-DOS.
 * SecureZIP is a brand name for new versions of PKZIP.
 * Windows Explorer:
 * Windows has had native support for ZIP files since Windows Me, and support was also included in the Windows 98 Plus! pack. Windows 98 Plus! and Windows Me sometimes saves ZIP passwords in the clear to the file Dynazip.log in the main Windows directory.
 * Windows 2000 does not have native support.
 * Windows XP has support.
 * Windows Vista and Windows Server 2008 can compress with Deflate64.
 * Windows Vista and Windows 7 cannot decrypt ZIP files natively, even files encrypted with previous versions of Windows Explorer.
 * WinZip is the software that first introduced compression methods 96 (12.0), 97 (11.0), and 98., the latest WinZip is 14.0 and the latest with new compression methods is 12.0 with LZMA and Compressed JPEG.  12.1 introduced the extension .zipx for ZIP files with nontraditional compression.

Compression methods
The most important methods for widespread support are 8 then 0. , far third might be 9.
 * Method 0 (Store) is no compression, and is not listed in the chart; all programs can at least read it.
 * Methods 2–5 (Reduce) usually only exist in files created in 1989 by PKZIP prior to 1.01.   Info-ZIP FTP site file claims: unreduce algorithm used in some early beta versions of PKZIP 2.0 and described in PKWARE's appnote.txt ... was never used in the "real" world
 * Method 8 (DEFLATE) is the compression method used by every ZIP archiver since 1993; support for this method is, as a practical matter, mandatory for compatibility with other ZIP archivers and the majority of ZIP files publicly available.
 * Method 9 (Deflate64) is called "enhanced deflate" by some software; PKWare claims a trademark on the name "Deflate64".
 * Method 10 (DCL Imploding) is sometimes referred to as "old IBM TERSE" in documentation, in contrast to method 18.
 * Method 12 (bzip2) was introducted with PKZIP and SecureZIP 6.0.
 * Method 18 (IBM TERSE) is sometimes referred to as "new IBM TERSE" in documentation, to distinguish from method 10.
 * Method 20 (Zstandard) was added to the PKZIP APPNOTE with version 6.3.7 in 2020, but, WinZip identifies it as method 93.
 * Method 93: see method 20 above.
 * Method 95 (XZ) is sometimes called "LZMA2". It was not supported in ZIP by 7-Zip until 15.05, despite the 7-Zip author also being the inventor of LZMA2.
 * Method 96 (Compressed JPEG) is a recompression method first introducted in WinZip 12.
 * Method 98 (PPMd Version I revision 1) was not supported as a writable format in ZIP by 7-Zip 4.65 despite PPMd being supported in 7-Zip's native 7z format.  It is supported from 9.11 on.

Older software versions in this table are those historically significant to the coverage of ZIP support, and/or were the last of their kind to support one of the old Implode or Reduce methods.

Security features

 * "Old" is the traditional ZIP password encryption from PKZIP 1 and 2; it is now considered easy to crack.
 * "WZ-AE" is AE-1 and AE-2, the secure AES encryption method introduced in WinZip 9.0
 * "SES-AES" is AES with the secure encryption method introduced in PKZIP/SecureZIP
 * "Directory encryption" indicates Central Directory Encryption &mdash; the ability to encrypt the headers and directory information itself