is License.  For example, you may
    not impose a license fee, royalty, or other charge for exercise of
    rights granted under this License, and you may not initiate litigation
    (including a cross-claim or counterclaim in a lawsuit) alleging that
    any patent claim is infringed by making, using, selling, offering for
    sale, or importing the Program or any portion of it.</p>

<h4>11. Patents.</h4>

<p>A &ldquo;contributor&rdquo; is a copyright holder who authorizes use under this
    License of th