PDF 'Meta-Data' and Formatting Tools:

• pdftk - allows changing page order, extracting pages, combining pages (or image files) to one pdf
• jPdf - similar features to pdftk; allows adding bookmars, renumbering pages, watermarks, attachments, encryptiong, signing, etc
• ABBYY FineReader (win) - OCR and image editing
• irfanview(win)/xnview(unix) - allows batch editing the extracted image files

Annotation:

• Okular - the KDE pdf viewer, annotation works well and fast, dark mode/light mode, -needs many KDE dependencies installed
• MasterPDF Editor - small, fast, many annotation features; -previous Okular annotations don't seem to show up? (don't know if incompatible)

Search:

• rga - ripgrep through the fulltext of all manner of files (zip, tar, epub,..) including pdf
• fast-p - extract and search through pdf fulltext with fzf