I've been using pdf.js for a while on my Windows box (where it is enabled by default on the FF beta channel) and it has performed remarkably well. Sometimes it's a bit slower than Adobe Reader or messes up colour or formatting, but on the whole I've quite enjoyed using it.
[0]: https://svn.torproject.org/svn/projects/design-paper/tor-des...
Note that the text in [0] doesn't scale properly, and the page previews in the navigation pane just show garbled text. Usable, but only just.
What's better is, it allows the (awesome) extension Pentadactyl to click the buttons in the viewer (since it's part of the browser). Have to click on (or tab to?) to the document itself though, in order to be able to use keyboard navigation on it though :-/
- renders very well
- is extremely slow on large documents with images, but pretty good with text-only ones
- offers a more integrated experience than Adobe's plugin
I think it's very promising, and I look forward to seeing it become more polished.
In about:config :
name: pdfjs.disabled status: default type: boolean value: false
So if at one point pdfjs should be enabled by default, they can just get rid of the preference in the default preferences file altogether instead of having to ship one where it says enabled: true (because absence of the value would be treated as false)