I read my articles on my (Android) tablet or on my computer (Ubuntu 12.10). On both, I want to be able to add notes and underline and highlight text. For Android there are various apps that allow you to to do this (the two I am currently using are RepliGo pdf reader and Moon+ reader, but there are more options). For Linux, I found it surprisingly difficult to find a package with good annotation capabilities.
Evince, the default pdf viewer on Ubuntu, allows to add notes for some time now, but unfortunately there are still no options for marking or underlining text. Moreover, it does not seem to be possible to edit or delete existing notes (although the latter should be possible in upcoming versions). So, what are the other options?
I used to use Adobe reader. However, with the latest Ubuntu 12.10, it is not available in Ubuntu software center anymore. You can manually download and install the Adobe Reader (Acroread) .deb package from its official website (make sure to install ia32-libs if you are running Ubuntu 64bits). However, when trying to install the downloaded .deb package, I got the warning that the package was of ‘bad quality’, so that was a no-go for me.
I have also used Foxit pdf reader in the past. It has good annotation capabilities, so I though I would give it another try. Like Adobe reader, you can download a .deb file from the developers website, and install it using the Ubuntu Software center (just double click the downloaded .deb file). Unfortunately, I got the same error message as above. There is also the possibility to run Foxit under Wine, but I rather have a ‘native’ solution.
Another great pdf viewer is Okular, which is an universal document viewer based on KPDF for KDE 4. This means Okular works on multiple platforms, including but not limited to Linux, Windows, Mac OS X, *BSD, etc. It has very good annotation options for quite some time now. However, annotations were not stored within the PDF documents, making this essentially useless for sharing (e.g., between tablet and computer).
But that has changed with the latest release, version 0.15! In this version, annotations are stored within the pdf file, so you can share your documents, including your annotations, with others or across devices. See for example the screenshot of a pdf file with annotations created in Okular.
The same pdf with annotations is displayed without problems in my pdf reader on my Android tablet, as shown below. Obviously, it works equally well the other way around.
Enough reasons to make this my default pdf viewer from now on.