Requirements
PDFlib Lite is available as open source. However, the PDFlib Lite license allows free use only under certain conditions. PDFlib Lite supports a subset of PDFlib's functionality; please see the PDFlib web site for details. The full version of PDFlib is available for download at » http://www.pdflib.com/products/pdflib-family/, but requires that you purchase a license for commercial use.
Issues with older versions of PDFlib
Any version of PHP 4 after March 9, 2000 does not support versions of PDFlib older than 3.0.
PDFlib 4.0 or greater is supported by PHP 4.3.0 and later.
Коментарии
The PDFlib Lite license cannot both be open source and have additional constraints placed on use. The exact licensing should be clarified.