This is qpdf version 11.9.0. This release includes some performance optimizations and reliability enhancements to JSON support, an enhanced command-line syntax for --pages in preparation for future options, support for multiple overlay and underlay specifications, and a few minor fixes and improvements to new features from qpdf 11.8.0.
For a full list of changes from previous releases, please see the release notes. See also README-what-to-download for details about the available source and binary distributions.