Reads and writes PDFs: subset/merge/rotate pages, modify metadata, build reusable Form XObjects, N-up and booklet layouts, watermarking (overlay/underlay), image and Form-XObject extraction, poster-sized output, and splitting 2-up PDFs; integrates with ReportLab (embedding existing PDF content into newly generated documents) and rst2pdf. No encryption/decryption support, and limited compression-filter support (external tools like pdftk needed for full decompression).