lxml is copyright Infrae and distributed under the BSD license (see
doc/licenses/BSD.txt), with the following exceptions:

Some code, such a selftest.py, selftest2.py and
src/lxml/_elementpath.py are derived from ElementTree and
cElementTree. See doc/licenses/elementtree.txt for the license text.

lxml.cssselect and lxml.html are copyright Ian Bicking and distributed
under the BSD license (see doc/licenses/BSD.txt).

test.py, the test-runner script, is GPL and copyright Shuttleworth
Foundation. See doc/licenses/GPL.txt. It is believed the unchanged
inclusion of test.py to run the unit test suite falls under the
"aggregation" clause of the GPL and thus does not affect the license
of the rest of the package.

The doctest.py module is taken from the Python library and falls under
the PSF Python License.

The isoschematron implementation uses several XSL and RelaxNG resources:
 * The (XML syntax) RelaxNG schema for schematron, copyright International
   Organization for Standardization (see 
   src/lxml/isoschematron/resources/rng/iso-schematron.rng for the license
   text)
 * The skeleton iso-schematron-xlt1 pure-xslt schematron implementation
   xsl stylesheets, copyright Rick Jelliffe and Academia Sinica Computing
   Center, Taiwan (see the xsl files here for the license text: 
   src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/)
 * The xsd/rng schema schematron extraction xsl transformations are unlicensed
   and copyright the respective authors as noted (see 
   src/lxml/isoschematron/resources/xsl/RNG2Schtrn.xsl and
   src/lxml/isoschematron/resources/xsl/XSD2Schtrn.xsl)

doc/licenses/BSD.txt:
Copyright (c) 2004 Infrae. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
   
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

  3. Neither the name of Infrae nor the names of its contributors may
     be used to endorse or promote products derived from this software
     without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INFRAE OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.