You may use the PyLD project under the terms of the New BSD License.

The New BSD License is recommended for most projects. It is simple and easy
to understand and it places almost no restrictions on what you can do with
the PyLD project.

You are free to use this project in commercial projects as long as the
copyright header is left intact.

If you are a commercial entity and use this set of libraries in your
commercial software then reasonable payment to Digital Bazaar, if you can
afford it, is not required but is expected and would be appreciated. If this
library saves you time, then it's saving you money. The cost of developing
the PyLD software was on the order of several hundred hours and tens of
thousands of dollars. We are attempting to strike a balance between helping
the development community while not being taken advantage of by lucrative
commercial entities for our efforts.

-------------------------------------------------------------------------------
New BSD License (3-clause)
Copyright (c) 2011, Digital Bazaar, Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * 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.
    * Neither the name of Digital Bazaar, Inc. 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 DIGITAL BAZAAR 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.
