I have used Diligent with great delight for many years, but am now looking to provide a "poor man's" option for a not-for-profit organization.  The only thing I've come up with so far is 'Wondershare PDFElement', with which I can combine multiple documents into one long pdf.  Individual license holders can annotate/highlight, etc., or - I can simply create one clean pdf for their use.  

I have a vague memory of a website option that actually allows for creation of a product that looks something like Diligent (i.e. a tabbed, page-numbered binder).  

Does anyone know of any options, or - is anyone familiar with PDFElement??  Thanks!!