PDF Studio is an easy to use yet powerful PDF editor. It maintains full compatibility with the PDF format and supports most PDF functions. It allows you to view, print, and search PDF files, review and annotate documents with text, graphics, and sound, scan to PDF, fill in and save forms, secure documents with passwords and permissions, merge, split, and assemble documents, convert Word, image, and text files to PDF, and add bookmarks, watermarks, headers, and footers. It is integrated with Google Apps and Sharepoint. The Pro version allows content editing, permanent manual redaction, batch processing, precision measuring tools, digital signatures, and preflight PDFs with PDF/X profiles.
Comments script with pagination adds comments to a website, paginating them without affecting the rest of the page content or the page URL. It can be used with multiple pages of a site, whatever the type of the page URL (modified or not with mod-rewrite). It can be set to allow only logged-in users to add comments, and has many other settings and Admin management.