how to modify pdf file on Ubuntu

[loody]

> The original post sounded like he wants to *edit* PDF's. I'd be
> interested in such things too...they seem rare even under Windows.
hi:
thanks all of your kind help.
I don't want to edit pdf like change the content or the layout it shows.
I just want to add bookmark, text comment, etc. such that at next time
while reading, I will remember what I thought previously.
Most reader is too simple. It only can READ.
pdfedit and kword seems too professional to me, since both of them can
change the content of pdf files.
I use acrobat profession 8 in xp previously. It can help me on what I
want to do, and press F8 and F9 can hide the menu and toolbar to let
my reading scope become larger.
I will try the tools you suggest to me.
appreciate your kind help,
miloody