What good libraries are there, in any common language, for converting PDF to HTML?
In Perl, you can use the SWISH::Filter plugin SWISH::Filters::Pdf2HTML. (It requires the xpdf package.)
For the reverse (HTML to PDF), see this question.
if you're looking for a way to convert PDF to HTML once or twice then I recommend Adobe Online Conversion
If it's an API you're after then http://www.pdfonline.com/ has an SDK that should suit your needs.
If it's a library you're after then please let us know which server-side language you prefer.
If you are working on a Windows box, I think Amyuni has a library for this as well. Their PDF Document Convertor is accessible as a DLL, can be used widely among the languages supported by Visual Studio, and can convert to RTF, TML, EXCEL, JPEG, and TIFF.
Given the vagueness of the original question I'm going to go ahead and give a solution that will work with any language that can execute command-line apps. Although it can be a little bit tricky to get setup, OpenOffice can be run in headless mode on a server and, with the help of jodconverter, can convert any file format to any other file format (well, any format conversions that openoffice can handle, that is).
Here are a couple of links that help with the setup:
http://www.lowagie.com/iText/ Opensource library for both Java and C#
Our service will take the URL of the webpage that you are wanting to convert, and return the PDF. It's not a library, but takes only 5 minutes to get working, so might be of value? URL is http://fourpdf.com/
Regards, Jake.
PDFBox at apache has an html extraction capability. http://pdfbox.apache.org/
The pdftohtml program converts pdf to html and xml and preserves position information of the text which is helpful for scraping tables..
It seems to be based on the xpdf library and has a windows binary, too.