OpenPDF uses dual licensing: when using the library, you may choose either Mozilla Public License Version 2.0 or GNU Lesser General Public License 2.1.
The SPDX license identifier for OpenPDF licensing is MPL-2.0 OR LGPL-2.1+
Please see https://www.mozilla.org/en-US/MPL/2.0/ or the attached file MPL-2.0.txt.
Please see https://www.gnu.org/licenses/old-licenses/lgpl-2.1 or the attached file LGPL-2.1.md.