[PaulHoule]

If you are doing some kind of intense annotation probably your most important thing is having an output format that supports the annotation you want to do -- not necessarily supporting any.

I have been thinking about universal annotation and the formats that I find the most interesting are PDF (because so much content exists in PDF) and HTML (open, easy to work with.)

[casvc]

You are absolutely right - we are thinking along the same lines. The only reason why we are offering TXT/IMG as output formats next to PDF/HTML is the fact that some people will have their own composite document formats and they can build those out of TXT/IMG.