libxml2 is an XML toolkit implemented in C, originally developed for the GNOME Project.

Official releases can be downloaded from https://download.gnome.org/sources/libxml2/

The git repository is hosted on GNOME's GitLab server: https://gitlab.gnome.org/GNOME/libxml2

Bugs should be reported at https://gitlab.gnome.org/GNOME/libxml2/-/issues.

Documentation is available at https://gitlab.gnome.org/GNOME/libxml2/-/wikis

This code is released under the MIT License, see the Copyright file.

This is open-source software written by hobbyists and maintained by volunteers.

It's NOT recommended to use this software to process untrusted data. There is a lot of ways that a malicious crafted xml could exploit a hidden vulnerability in the software.

The software is provided "as is", without warranty of any kind, express or implied. Use this software at your own risk.

To report security bugs, you can create a confidential issue with the "security" label. We will review and work on it as a best effort. But remember that this is a community project, maintained by volunteer developers, so if you are concern about any important security bug that's critical for you, feel free to collaborate and provide a patch.

The main rule is to be kind. Do not pressure developers to fix a CVE or to work on a functionality that you need, because that won't work. This is a community project, developers will work in the issues that they consider interesting and when they want. All contributions are welcome, so if something is important for you, you can always get involved, implement it yourself and be part of the open source community.

libxml2 can be built with GNU Autotools, CMake or meson.

If you build from a Git tree, you have to install Autotools and start by generating the configuration files with:

./autogen.sh [configuration options]

If you build from a source tarball, extract the archive with:

tar xf libxml2-xxx.tar.gz
cd libxml2-xxx

Then you can configure and build the library:

./configure [configuration options]
make

The following options disable or enable code modules and relevant symbols:

--with-c14n Canonical XML 1.0 support (on)
--with-catalog XML Catalogs support (on)
--with-debug debugging module (on)
--with-docs Build documentation (off)
--with-history history support for xmllint shell (off)
--with-readline[=DIR] use readline in DIR for shell (off)
--with-html HTML parser (on)
--with-http ABI compatibility for removed HTTP support (off)
--with-iconv[=DIR] iconv support (on)
--with-icu ICU support (off)
--with-iso8859x ISO-8859-X support if no iconv (on)
--with-modules dynamic modules support (on)
--with-output serialization support (on)
--with-pattern xmlPattern selection interface (on)
--with-push push parser interfaces (on)
--with-python Python bindings (off)
--with-reader xmlReader parsing interface (on)
--with-regexps regular expressions support (on)
--with-relaxng RELAX NG support (on)
--with-sax1 older SAX1 interface (on)
--with-schemas XML Schemas 1.0 support (on)
--with-schematron Schematron support (off)
--with-threads multithreading support (on)
--with-thread-alloc per-thread malloc hooks (off)
--with-valid DTD validation support (on)
--with-winpath Windows path support (on for Windows)
--with-writer xmlWriter serialization interface (on)
--with-xinclude XInclude 1.0 support (on)
--with-xpath XPath 1.0 support (on)
--with-xptr XPointer support (on)
--with-zlib[=DIR] use libz in DIR (off)

Other options:

--prefix=DIR set installation prefix
--with-minimum build a minimally sized library (off)
--with-legacy maximum ABI compatibility (off)

Note that by default, no optimization options are used. You have to enable them manually, for example with:

CFLAGS='-O2 -fno-semantic-interposition' ./configure

Now you can run the test suite with:

make check

Please report test failures to the bug tracker.

Then you can install the library:

make install

At that point you may have to rerun ldconfig or a similar utility to update your list of installed shared libs.

Example commands:

cmake -E tar xf libxml2-xxx.tar.xz
cmake -S libxml2-xxx -B builddir [options]
cmake --build builddir
ctest --test-dir builddir
cmake --install builddir

Common CMake options include:

-D BUILD_SHARED_LIBS=OFF # build static libraries
-D CMAKE_BUILD_TYPE=Release # specify build type (single-config)
--config Release # specify build type (multi-config)
-D CMAKE_INSTALL_PREFIX=/usr/local # specify the install path
-D LIBXML2_WITH_ICONV=OFF # disable iconv
-D LIBXML2_WITH_ZLIB=ON # enable zlib

You can also open the libxml source directory with its CMakeLists.txt directly in various IDEs such as CLion, QtCreator, or Visual Studio.

Example commands:

meson setup [options] builddir
ninja -C builddir
meson test -C builddir
ninja -C builddir install

See the meson_options.txt file for options. For example:

-Dprefix=$prefix
-Dhistory=enabled
-Dschemas=disabled
-Dzlib=enabled

libxml2 supports POSIX and Windows operating systems.

The iconv function is required for conversion of character encodings. This function is part of POSIX.1-2001. If your platform doesn't provide iconv, you need an external libiconv library, for example GNU libiconv. Using ICU is also supported but discouraged.

The xmllint executable uses libreadline and libhistory if enabled.

Besides build system tools, only a C compiler should be required. Reconfiguration of the Autotools build requires the pkg.m4 macro from pkg-config. Building the documentation requires Doxygen, xsltproc and the DocBook 4 XSLT stylesheets. Building the Python bindings requires Doxygen.

The current version of the code can be found in GNOME's GitLab at https://gitlab.gnome.org/GNOME/libxml2. The best way to get involved is by creating issues and merge requests on GitLab.

All code must conform to C89 and pass the GitLab CI tests. Add regression tests if possible.

No LLMs for issues.

No LLMs for patches / pull requests.

No LLMs for comments on the bug tracker, including translation.

English is encouraged, but not required. You are welcome to post in your native language and rely on others to have their own translation tools of choice to interpret your words.

• Daniel Veillard
• Bjorn Reese
• William Brack
• Igor Zlatkovic for the Windows port
• Aleksey Sanin
• Nick Wellnhofer