In order to create I had to figure out how to convert PDFs to HTML using PHP.

The trick is to use a Java program called pdfbox and run it from the shell using PHP:

exec('java -Xmx32m -jar pdfbox-app-1.8.2.jar ExtractText -html '.$filename.' '.$filename.'.html');

The code above fires up pdfbox and converts the file at path $filename into the HTML file at $filename.html. It's fast, works well and it's easy (tested on a Dreamhost shared hosting account - should run most places).