Evaluate various open-source PDF libraries

[HalosGhost]

If possible, our lives could be made much simpler if there are already PDF libraries out there which allow us to parse a PDF and query specific properties of it. There are many considerations for whether or not a library is reasonable for us to use:

• Is the license compatible with us?
• Is the library written in (or trivially callable from) C?
• Does it allow querying all the things we need (e.g., tags, replacement text, etc.)?
• Is it a reasonable size?
• Is it easy to use?

If we cannot find a library which meets these criteria, we may need to look into implementing basic PDF parsing and querying ourselves.

[HalosGhost]

Some initial libraries to review:

• [ ] libpoppler (based on xpdf)
• [ ] libcairo
• [ ] libxpdf
• [ ] ghostscript
• [ ] mupdf
• [ ] jagpdf

[HalosGhost]

Apparently, Libreoffice has the ability to export tagged PDFs! LO uses various document libraries for export and document compatibility. The first library to evaluate should be these to see if these libraries explicitly support PDF parsing (even minimally) and/or PDF exporting with tags.