TITLE: Math Annotate Platform?
QUESTION [72 upvotes]: Suppose most mathematical research papers were freely accessible online. 
Suppose a well-organized platform existed where responsible users could write comments on any paper (linking to its doi, Arxiv number, or other electronic identifier from which it could be retrieved freely), or even ``mark it up'' (pointing to similar arguments elsewhere, catch and correct mistakes, e.g.), and where you could see others' comments and mark-ups. 
Would this be, or evolve into, a useful tool for mathematical research? What features would be necessary, useful, or to-be-avoided-at-all-costs? 
This is not a rhetorical question: a committee of the National Research Council is looking into what could be built on top of a World Digital Math Library, to make it even more useful to the mathematical community than having all the materials available. This study is being funded by the Sloan Foundation. 
Input from the mathematical community would be very useful.

REPLY [3 votes]: Having read and followed numerous discussion on the subject,
it seems that possible downsides arise from having comments or discussions unwanted by the authors of the article. 
However, enabling the authors to moderate all comments themselves would seem
to address those concerns. That is, when the authors would receive the comments first and then decide whether to make them public. Of course, that would include  the possible decision by the authors not to receive any comments at all, a decision that they should also be able to reverse at any time in the future.
Basically, since the authors are the ones who wrote the paper, they should own all the corresponding rights, including any comments and moderation.