- WIMLIB
-
-This is wimlib version 0.7.2 (May 2012). wimlib can be used to read, write,
-and mount files in the Windows Imaging Format (WIM files). These files are
-normally created by using the `imagex.exe' utility on Windows, but this library
-provides a free implementetion of imagex for UNIX-based systems.
-
-The main use of this library is to create customized images of Windows PE, the
-Windows Preinstallation Environment, without having to rely on Windows. Windows
-PE is a lightweight version of Windows that can run entirely from memory and can
-be used to install Windows from local media or a network drive or perform
-maintenance. Windows PE is the operating system that runs when you boot from
-the Windows DVD.
-
-You can find Windows PE on the ISO filesystem on the installation DVD for both
-Windows 7 and Windows 8. I don't have a DVD for Vista but it should be on there
-too. The Windows PE image is a WIM file, `sources/boot.wim', on the ISO
-filesystem. Windows PE can also be found in the Windows Automated Installation
-Kit (WAIK), which is free to download from Microsoft, inside the `WinPE.cab'
-file, which you can extract if you install either the `cabextract' or `p7zip'
-programs.
-
-wimlib provides a public API for other programs to use, but also comes with two
-programs: `imagex' and `mkwinpeimg'.
-
-`imagex' is intended to be like the imagex.exe program from Windows. `imagex'
-can be used to create, extract, and mount WIM files. Both read-only and
-read-write mounts are supported. See the man page `doc/imagex.1' for more
-details.
-
-`mkwinpeimg' is shell script that makes it easy to create a customized bootable
-image of Windows PE that can be put on a CD or USB drive, or published on a
-server for PXE booting. See the main page `doc/mkwinpeiso.1' for more details.
-
-wimlib can also be used to handle larger WIM files such as the `install.wim'
-file that comes on the Windows DVD. You may not, however, losslessly capture
-and apply Windows installations using wimlib because of issues with NTFS and
-Windows-specific information.
-
-An earlier version of Wimlib is being used to deploy Windows 7 from the Ultimate
-Deployment Appliance. For more information see
-http://www.ultimatedeployment.org/.
-
- CONFIGURATION
-
-Besides the various well-known options, the following options can be passed to
-wimlib's `configure' script:
+ INTRODUCTION
+
+This is wimlib version 1.6.0 (January 2014). wimlib is a C library for
+creating, modifying, extracting, and mounting files in the Windows Imaging
+Format (WIM files). These files are normally created using the ImageX
+(imagex.exe) or Dism (Dism.exe) utilities on Windows, but wimlib is distributed
+with a free implementation of ImageX called "wimlib-imagex" for both UNIX-like
+systems and Windows.
+
+ INSTALLATION
+
+To install wimlib and wimlib-imagex on Windows you simply need to download and
+extract the ZIP file containing the latest binaries from the SourceForge page
+(http://sourceforge.net/projects/wimlib/), which you may have already done.
+
+To install wimlib and wimlib-imagex on UNIX-like systems (with Linux being the
+primary supported and tested platform), you must compile the source code, which
+is also available at http://sourceforge.net/projects/wimlib/. Alternatively,
+check if a package has been prepared for your Linux distribution. Example files
+for Debian and RPM packaging are in the debian/ and rpm/ directories.
+
+ WIM FILES
+
+A Windows Imaging (WIM) file is an archive designed primarily for archiving
+Windows filesystems. However, it can be used on other platforms as well, with
+some limitations. Like some other archive formats such as ZIP, files in WIM
+archives may be compressed. WIM files support multiple compression formats,
+including LZX, XPRESS, and LZMS. All these formats are supported by wimlib.
+
+A WIM file consists of one or more "images". Each image is an independent
+top-level directory structure and is logically separate from all other images in
+the WIM. Each image has a name as well as a 1-based index in the WIM file. To
+save space, WIM archives automatically combine all duplicate files across all
+images.
+
+A WIM file may be either stand-alone or split into multiple parts. Split WIMs
+are read-only and cannot be modified.
+
+ IMAGEX IMPLEMENTATION
+
+wimlib itself is a C library, and it provides a documented public API (See:
+http://wimlib.sourceforge.net) for other programs to use. However, it is also
+distributed with a command-line program called "wimlib-imagex" that uses this
+library to implement an imaging tool similar to Microsoft's ImageX.
+wimlib-imagex supports almost all the capabilities of Microsoft's ImageX as well
+as additional capabilities. wimlib-imagex works on both UNIX-like systems and
+Windows, although some features differ between the platforms.
+
+Run `wimlib-imagex' with no arguments to see an overview of the available
+commands and their syntax. For additional documentation:
+
+ * If you have installed wimlib-imagex on a UNIX-like system, you will find
+ further documentation in the man pages; run `man wimlib-imagex' to get
+ started.
+
+ * If you have downloaded the Windows binary distribution, you will find the
+ documentation for wimlib-imagex in PDF format in the "doc" directory,
+ ready for viewing with any PDF viewer. Please note that although the PDF
+ files are converted from UNIX-style "man pages", they do document
+ Windows-specific behavior when appropriate.
+
+ COMPRESSION RATIO
+
+wimlib (and wimlib-imagex) can create XPRESS, LZX, or LZMS compressed WIM
+archives. wimlib includes its own compression codecs and does not use the
+compression API available on some versions of Windows. The below table provides
+the results (file size, in bytes, and time to create, in seconds) of capturing a
+WIM containing a x86 Windows PE image, using various compression types and
+options. When applicable, the results with the equivalent Microsoft
+implementation in WIMGAPI, which is the library used by ImageX and Dism, are
+included.
+
+ ===========================================================================
+ | Compression type || wimlib (v1.6.1) | WIMGAPI (Windows 8) |
+ ===========================================================================
+ | None [1] || 531,979,435 in 18s | 531,980,333 in 24s |
+ | XPRESS [2] || 207,369,912 in 22s | 209,886,010 in 39s |
+ | LZX (quick) [3] || 194,876,901 in 29s | N/A |
+ | LZX (normal) [4] || 187,962,713 in 158s | 188,163,523 in 125s |
+ | LZX (slow) [5] || 186,913,423 in 358s | N/A |
+ | LZMS (non-solid) [6] || 176,880,594 in 182s | N/A |
+ | LZMS (solid) [7] || 136,507,304 in 494s | 126,735,608 in 623s |
+ ===========================================================================
+
+Notes:
+ [1] '--compress=none' for wimlib-imagex;
+ '/compress none' or no option for ImageX.
+
+ [2] '--compress=fast' or '--compress=XPRESS' for wimlib-imagex;
+ '/compress fast' or no option for ImageX.
+ Compression chunk size is 32768 (the default for XPRESS).
+
+ [3] No compression option specified to wimlib-imagex; no known equivalent for
+ WIMGAPI (ImageX uses XPRESS compression if no option specified).
+ Compression chunk size is 32768 (the default for LZX).
+
+ [4] '--compress=maximum' or '--compress=LZX' for wimlib-imagex;
+ '/compress maximum' for ImageX.
+ Compression chunk size is 32768 (the default for LZX).
+
+ [5] '--compress=maximum --compress-slow' for wimlib-imagex;
+ no known equivalent for WIMGAPI.
+ Compression chunk size is 32768 (the default for LZX).
+
+ [6] '--compress=recovery' or '--compress=LZMS' for wimlib-imagex;
+ no known way to create the equivalent with WIMGAPI.
+ Compression chunk size is 131072 (the default for LZMS). Note: this
+ compression type is not generally recommended due to its limited
+ compatibility with the MS implementations.
+
+ [7] '--compress=recovery --solid' or '--compress=LZMS --solid' for
+ wimlib-imagex; WIMCreateFile with WIM_COMPRESSION_LZMS and flag
+ 0x20000000 for WIMGAPI. Compression chunk size in packed resources is
+ 33554432 for wimlib, 67108864 for WIMGAPI. Note: this compression type
+ is not generally recommended due to its limited compatibility with the MS
+ implementations. Also, due to the large chunk size, wimlib uses about
+ 500MB of memory per thread when compressing in this format.
+
+The above timings were done on Windows 8 (x86) so that side-by-side comparisons
+with the Microsoft implementation would be possible; however, wimlib may have
+even better performance on other operating systems such as Linux. The system
+had 2 CPUs and 2 GiB of memory available. All times were done with the page
+cache warmed, so the times primarily measure the performance of the compression
+algorithms and not the time to read data from disk, which presumably is similar
+in each implementation.
+
+Below are results for compressing the Canterbury corpus using wimlib (v1.6.1),
+WIMGAPI (Windows 8), and some other formats/programs, including the archive size
+only. Note that the Canterbury corpus includes no duplicate files or hard
+links, which WIM handles better than most other formats by storing only distinct
+data streams.
+
+ =================================================
+ | Format | Size (bytes) |
+ =================================================
+ | tar | 2,826,240 |
+ | WIM (WIMGAPI, None) | 2,814,278 |
+ | WIM (wimlib, None) | 2,813,856 |
+ | WIM (WIMGAPI, XPRESS) | 825,410 |
+ | WIM (wimlib, XPRESS) | 792,024 |
+ | tar.gz (gzip, default) | 738,796 |
+ | ZIP (Info-ZIP, default) | 735,334 |
+ | tar.gz (gzip, -9) | 733,971 |
+ | ZIP (Info-ZIP, -9) | 732,297 |
+ | WIM (wimlib, LZX quick) | 722,196 |
+ | WIM (WIMGAPI, LZX) | 651,766 |
+ | WIM (wimlib, LZX normal) | 639,464 |
+ | WIM (wimlib, LZX slow) | 633,144 |
+ | WIM (wimlib, LZMS non-solid) | 590,252 |
+ | tar.bz2 (bzip, default) | 565,008 |
+ | tar.bz2 (bzip, -9) | 565,008 |
+ | WIM (wimlib, LZMS solid) | 534,218 |
+ | WIM (wimlib, LZMS solid, slow) | 529,904 |
+ | WIM (WIMGAPI, LZMS solid) | 521,232 |
+ | tar.xz (xz, default) | 486,916 |
+ | tar.xz (xz, -9) | 486,904 |
+ | 7z (7-zip, default) | 484,700 |
+ | 7z (7-zip, -9) | 483,239 |
+ =================================================
+
+ NTFS SUPPORT
+
+WIM images may contain data, such as alternate data streams and
+compression/encryption flags, that are best represented on the NTFS filesystem
+used on Windows. Also, WIM images may contain security descriptors which are
+specific to Windows and cannot be represented on other operating systems.
+wimlib handles this NTFS-specific or Windows-specific data in a
+platform-dependent way:
+
+ * In the Windows version of wimlib and wimlib-imagex, NTFS-specific and
+ Windows-specific data are supported natively.
+
+ * In the UNIX version of wimlib and wimlib-imagex, NTFS-specific and
+ Windows-specific data are ordinarily ignored; however, there is also special
+ support for capturing and extracting images directly to/from unmounted NTFS
+ volumes. This was made possible with the help of libntfs-3g from the
+ NTFS-3g project.
+
+For both platforms the code for NTFS capture and extraction is complete enough
+that it is possible to apply an image from the "install.wim" contained in recent
+Windows installation media (Vista, Windows 7, or Windows 8) directly to a NTFS
+filesystem, and then boot Windows from it after preparing the Boot Configuration
+Data. In addition, a Windows installation can be captured (or backed up) into a
+WIM file, and then re-applied later.
+
+ WINDOWS PE
+
+A major use for wimlib and wimlib-imagex is to create customized images of
+Windows PE, the Windows Preinstallation Environment, on either UNIX-like systems
+or Windows without having to rely on Microsoft's software and its restrictions
+and limitations.
+
+Windows PE is a lightweight version of Windows that can run entirely from memory
+and can be used to install Windows from local media or a network drive or
+perform maintenance. It is the operating system that runs when you boot from
+the Windows installation media.
+
+You can find Windows PE on the installation DVD for Windows Vista, Windows 7, or
+Windows 8, in the file `sources/boot.wim'. Windows PE can also be found in the
+Windows Automated Installation Kit (WAIK), which is free to download from
+Microsoft, inside the `WinPE.cab' file, which you can extract natively on
+Windows, or on UNIX-like systems if you install either the `cabextract' or
+`p7zip' programs.
+
+In addition, Windows installations and recovery partitions frequently contain a
+WIM containing an image of the Windows Recovery Environment, which is similar to
+Windows PE.
+
+A shell script `mkwinpeimg' is distributed with wimlib on UNIX-like systems to
+ease the process of creating and customizing a bootable Windows PE image.
+
+ DEPENDENCIES
+
+This section documents the dependencies of wimlib and the programs distributed
+with it, when building for a UNIX-like system from source. If you have
+downloaded the Windows binary distribution of wimlib and wimlib-imagex then all
+dependencies were already included and this section is irrelevant.
+
+* libxml2 (required)
+ This is a commonly used free library to read and write XML files. You
+ likely already have it installed as a dependency for some other program.
+ For more information see http://xmlsoft.org/.
+
+* libfuse (optional but highly recommended)
+ Unless configured with --without-fuse, wimlib requires a non-ancient
+ version of libfuse to be installed. Most Linux distributions already
+ include this, but make sure you have the libfuse package installed, and
+ also libfuse-dev if your distribution distributes header files
+ separately. FUSE also requires a kernel module. If the kernel module
+ is available it will automatically be loaded if you try to mount a WIM
+ file. For more information see http://fuse.sourceforge.net/. FUSE is
+ also available for FreeBSD.
+
+* libntfs-3g (optional but highly recommended)
+ Unless configured with --without-ntfs-3g, wimlib requires the library
+ and headers for libntfs-3g version 2011-4-12 or later to be installed.
+ Versions dated 2010-3-6 and earlier do not work because they are missing
+ the header xattrs.h (and the file xattrs.c, which contains functions we
+ need). libntfs-3g version 2013-1-13 is compatible only with wimlib
+ 1.2.4 and later.
+
+* OpenSSL / libcrypto (optional)
+ wimlib can use the SHA1 message digest code from OpenSSL instead of
+ compiling in yet another SHA1 implementation. (See LICENSE section.)
+
+* cdrkit (optional)
+* mtools (optional)
+* syslinux (optional)
+* cabextract (optional)
+ The `mkwinpeimg' shell script will look for several other programs
+ depending on what options are given to it. Depending on your Linux
+ distribution, you may already have these programs installed, or they may
+ be in the software repository. Making an ISO filesystem requires
+ `mkisofs' from `cdrkit' (http://www.cdrkit.org). Making a disk image
+ requires `mtools' (http://www.gnu.org/software/mtools) and `syslinux'
+ (http://www.syslinux.org). Retrieving files from the Windows Automated
+ Installation Kit requires `cabextract' (http://www.cabextract.org.uk).
+
+ CONFIGURATION
+
+This section documents the most important options that may be passed to the
+"configure" script when building from source:
+
+--without-ntfs-3g
+ If libntfs-3g is not available or is not version 2011-4-12 or later,
+ wimlib can be built without it, in which case it will not be possible to
+ apply or capture images directly to/from NTFS volumes.
--without-fuse
If libfuse or the FUSE kernel module is not available, wimlib can be
compiled with --without-fuse. This will remove the ability to mount and
- unmount WIM files. wimlib_mount() and wimlib_unmount() will fail with
- WIMLIB_ERR_UNSUPPORTED.
+ unmount WIM files.
--without-libcrypto
Build in functions for SHA1 rather than using external SHA1 functions
from libcrypto (part of OpenSSL). The default is to use libcrypto if it
is found on the system.
+--enable-xattr, --disable-xattr
+ Enable or disable support for the extended-attributes interface to NTFS
+ alternate data streams in mounted WIMs. To support these, wimlib
+ requires that the setxattr() function and the attr/xattr.h header are
+ available. The default is to autodetect whether support is possible.
+
+--disable-multithreaded-compression
+ By default, data will be compressed using multiple threads when writing
+ a WIM, unless only 1 processor is detected. Specify this option to
+ disable support for this.
+
--enable-ssse3-sha1
Use a very fast assembly language implementation of SHA1 from Intel.
Only use this if the build target supports the SSSE3 instructions.
---disable-custom-memory-allocator
- If this option is given, MALLOC(), FREE(), CALLOC(), and STRDUP() will
- directly call the appropriate functions in the C library.
- wimlib_set_memory_allocator() will fail with WIMLIB_ERR_UNSUPPORTED.
-
---disable-verify-compression
- Unless this option is given, every time wimlib compresses a data block
- it will decompress it into a temporary buffer and abort() the program
- with an error message if the decompressed data does not exactly match
- the original data. This is to find bugs.
-
---disable-security-data
- Wimlib cannot create or modify WIM security data, but by default it will
- copy existing security data when modifying a WIM or exporting an image.
- Passing this flag will disable this support; then wimlib will always
- write WIMs without security data.
-
--disable-error-messages
- Removes all error messages from the library. If left in, they still
- have to explicitly turned on with wimlib_set_print_errors() in order to
- see them. Also, error codes will still be returned regardless of
- whether error messages are printed or not.
-
- If --disable-error-messages is given, wimlib_set_print_errors() will
- fail with WIMLIB_ERR_UNSUPPORTED if the action is to turn error messages
- on.
+ Save some space by removing all error messages from the library.
--disable-assertions
- Remove all assertions. Without this option, wimlib will abort() the
- program if an assertion fails. An assertion failure should only occur
- if there is a bug in wimlib.
-
---enable-debug
- Include debugging messages. Only use this option if you have found a
- bug in the library.
-
---enable-more-debug
- Include more debugging messages. Only use this option if you have found
- a bug in the library.
-
- DEPENDENCIES
+ Remove assertions included by default.
-Wimlib requires libxml2 to build. This is a commonly used free library to read
-and write XML files. You likely already have it installed as a dependency for
-some other program. For more information see http://xmlsoft.org/.
+ PORTABILITY
-Wimlib also requires libfuse to build (unless configured with --without-fuse;
-see above). Most GNU/Linux distributions already include this, but make sure
-you have the libfuse package installed (libfuse-dev if your distribution
-distributes header files separately). FUSE also requires a kernel module. If
-the kernel module is available it will automatically be loaded if you try to
-mount a WIM file. For more information see http://fuse.sourceforge.net/. FUSE
-is also available for FreeBSD.
+wimlib has primarily been tested on Linux and Windows (primarily Windows 7, but
+also Windows XP and Windows 8).
-The `mkwinpeimg' shell script will look for several other programs depending on
-what options are given to it. Depending on your GNU/Linux distribution, you may
-already have these programs installed, or they may be in the software
-repository. Making an ISO filesystem requires `mkisofs' from `cdrkit'
-(http://www.cdrkit.org). Making a disk image requires `mtools'
-(http://www.gnu.org/software/mtools) and `syslinux' (http://www.syslinux.org).
-Retrieving files from the Windows Automated Installation Kit requires
-`cabextract' (http://www.cabextract.org.uk).
+wimlib may work on FreeBSD and Mac OS X. However, this is not well tested. If
+you do not have libntfs-3g 2011-4-12 or later available, you must configure
+wimlib with --without-ntfs-3g. On FreeBSD, before mounting a WIM you need to
+load the POSIX message queue module (run `kldload mqueuefs').
- PORTABILITY
+The code has primarily been tested on x86 and x86_64 CPUs, but it's written to
+be portable to other architectures and I've also tested it on ARM. However,
+although the code is written to correctly deal with endianness, it has not yet
+actually been tested on a big-endian architecture.
-wimlib has mostly been developed and tested on x86_64 (64-bit) GNU/Linux.
+ REFERENCES
-It has been tested on x86 (32-bit) GNU/Linux occasionally.
+The WIM file format is partially specified in a document that can be found in
+the Microsoft Download Center. However, this document really only provides an
+overview of the format and is not a formal specification.
-It can also be compiled and run on FreeBSD.
+With regards to the supported compression formats:
-wimlib should work on big endian machines but it has not been tested.
+- Microsoft has official documentation for XPRESS that is of reasonable quality.
+- Microsoft has official documentation for LZX but it contains errors.
+- There does not seem to be any official documentation for LZMS, so my comments
+ and code in src/lzms-decompress.c may in fact be the best documentation
+ available for this particular compression format.
-There are no plans to port wimlib to Windows since the programming interface on
-Windows is very different and Microsoft's imagex.exe is already available.
+The code in ntfs-3g_apply.c and ntfs-3g_capture.c uses the NTFS-3g library,
+which is a library for reading and writing to NTFS filesystems (the filesystem
+used by recent versions of Windows). See
+http://www.tuxera.com/community/ntfs-3g-download/ for more information.
- REFERENCES
+The LZX decompressor (lzx-decompress.c) was originally based on code from the
+cabextract project (http://www.cabextract.org.uk) but has been rewritten.
-The WIM file format is specified in a document that can be found in the
-Microsoft Download Center. There is a similar document that specifies the LZX
-compression format, and a document that specifies the XPRESS compression format.
-However, some aspects of these formats are poorly documented. Some particularly
-poorly documented parts of the formats have had comments added in various places
-in the library.
+The LZX compressor (lzx-compress.c) was originally based on code written by
+Matthew Russotto (www.russotto.net/chm/) but has been rewritten. It now uses
+suffix array construction code from divsufsort
+(https://code.google.com/p/libdivsufsort/) and algorithms from 7-Zip as well as
+several published papers.
-lzx-decomp.c, the code to decompress WIM file resources that are compressed
-using LZX compression, is originally based on code from the cabextract project
-(http://www.cabextract.org.uk).
+lz_hash.c contains a hash-table-based LZ77 matchfinder that is based on code
+from zlib but has been rewritten. This code is applicable to XPRESS, LZX, and
+LZMS, all of which are partly based on LZ77 compression.
-lzx-comp.c, the code to compress WIM file resources using LZX compression, is
-originally based on code written by Matthew Russotto (www.russotto.net/chm/).
+A limited number of other free programs can handle some parts of the WIM
+file format:
-lz.c, the code to find LZ77 matches (used for both XPRESS and LZX compression),
-is based on code from zlib.
+ * 7-zip is able to extract and create WIMs (as well as files in many
+ other archive formats). However, wimlib is designed specifically to handle
+ WIM files and provides features previously only available in Microsoft's
+ implementation, such as the ability to mount WIMs read-write as well as
+ read-only, the ability to create LZX or XPRESS compressed WIMs, and the
+ correct handling of security descriptors and hard links.
+ * ImagePyX (https://github.com/maxpat78/ImagePyX) is a Python program that
+ provides similar capabilities to wimlib-imagex. One thing to note, though,
+ is that it does not support compression and decompression by itself, but
+ instead relies on external native code, such as the codecs from wimlib.
-A very limited number of other free programs can handle some parts of the WIM
-file format. 7-zip is able to extract and create WIMs (as well as files in many
-other archive formats). However, wimlib is designed specifically to handle WIM
-files and provides features previously only available in Microsoft's imagex.exe,
-such as the ability to mount WIMs read-write as well as read-only, and the
-ability to create LZX or XPRESS compressed WIMs.
+A very early version of wimlib is being used to deploy Windows 7 from the
+Ultimate Deployment Appliance. For more information see
+http://www.ultimatedeployment.org/.
- MORE INFORMATION
+If you are looking for a UNIX archive format that provides features similar to
+WIM, I recommend you take a look at SquashFS (http://squashfs.sourceforge.net/).
-See the manual pages for `imagex', the manual pages for the subcommands of
-`imagex', and the manual page for `mkwinpeimg'.
+ LICENSE
-As of version 0.5.0, Wimlib's public API is documented. Doxygen is required to
-build the documentation. To build the documentation, run `configure', then
-enter the directory `doc' and run `doxygen'. The HTML documentation will be
-created in a directory named `html'.
+As of version 1.0.0, wimlib and all programs and scripts distributed with it are
+released under the GNU GPL version 3.0 or later.
- LICENSE
+wimlib is independently developed and does not contain any code, data, or files
+copyrighted by Microsoft. It is not known to be affected by any patents.
-Wimlib is released under the GNU LGPL version 2.1 or later. The files in the
-`programs' directory are released under the GPL version 3.
+On UNIX-like systems, if you do not want wimlib to be dynamically linked with
+libcrypto (OpenSSL), configure with --without-libcrypto. This replaces the SHA1
+implementation with built-in code and there will be no difference in
+functionality.
- DISCLAIMER
+ DISCLAIMER
-Wimlib is experimental. Use Microsoft's `imagex.exe' if you want to make sure
-your WIM files are made correctly. Please submit a bug report (to
-ebiggers3@gmail.com) if you find a bug.
+wimlib comes with no warranty whatsoever. Please submit a bug report (to
+ebiggers3@gmail.com) if you find a bug in wimlib and/or wimlib-imagex.
-Some parts of the WIM file format are poorly documented or even completely
-undocumented, so I've just had to do the best I can to read and write WIMs that
-appear to be compatible with Microsoft's software.
+Be aware that some parts of the WIM file format are poorly documented or even
+completely undocumented, so I've just had to do the best I can to read and write
+WIMs that appear to be compatible with Microsoft's software.
git://wimlib.net / wimlib / blobdiff