If you want to edit every aspect of a PDF, including the content and the layout, you're going to need a professional tool like Adobe Acrobat. If all you want to do is split one PDF into two, or combine two PDF's into one, I Love PDF can do the job for you.
If you have a PDF file that you need to display on the web in HTML, than this website is exactly what you need. PDF files were not designed to be displayed right in browsers, and sometime converting them to HTML is the best way to display them. Using this service, the process couldn't be easier.
Its contents are now freely available as a series of high resolution (228MB) PDF sections available here [kitchin.org]. The book gives an interesting overview of the early years of (more popular forms) of data visualization, including chapters about mappi
Brainshark is a competitor to Slideshare.net, allowing anyone to upload a PowerPoint or PDF to their Web service and annotate the visuals with audio/video comments or music.
Copy editing on paper is easy: just mark everything up with a red pen. Online can get complicated. Sure, you can use the track changes feature in Microsoft Office combined with the notes function, but that's not as efficient as it could be. If you're looking for a different way, check out CrocoDoc.
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