This is in low maintanance mode.
I don't use it nowadays except for the rare cases in which I have to add page numbers to PDF files.
For all other PDF manipulation I suggest you use pdfarranger.
Logo from kgullion provided here.
PDFsak (PDF Swiss Army knife) is an utility to manipulate PDF files.
The previous name of the project (as of 2021-10-10) was "pdftools".
It allows you to:
PDFsak has been tested on Windows and Linux (Fedora).
It should work also on macOS, although it has not been tested on this platform.
Checkout the online documentation for requirements, installation, usage and examples.