Highlight Text Or Annotate PDF Files In Ubuntu With Xournal

Xournal is an application for note taking or sketching and even though its page says it's a tool similar to Microsoft Windows Journal, Jarnal, Gournal, and NoteLab, I'd also add Foxit Reader to the list.

 

That's because even though its Sourceforge page doesn't mention this, Xournal can also be used as a lightweight PDF viewer and further more, it can be used to highlight text in PDF documents, make annotations and so on.