It's a browser extension, but the benefit of web apps in general is portability. This one has the advantage (from the looks of it) of solving a very hard proble

It's a browser extension, but the benefit of web apps in general is portability. This one has the advantage (from the looks of it) of solving a very hard problem, that of being able to view and manipulate pdf files. AFAIK there is no other easy and free way to do this in Linux, for one. edit: It doesn't appear to let you edit a pdf, just annotate. Which is still incredibly useful to be able to do alone or collaboratively.