Ubuntu / Linux pdf reader / editor

• Foxit Reader - View, create, convert, annotate, print, collaborate, share, fill forms and sign.
• xpdf - Install xpdf "Xpdf is a small and efficient program which uses standard X fonts". Lightweight, but with outdated interface.
• evince - Install evince Evince is a document viewer for multiple document formats. Used by default on Gnome.
• kpdf - Install kpdf KPDF is a pdf viewer based on xpdf for KDE 3.
• gv - Install gv - an old lightweight pdf viewer with an old interface. Size of the package is only 580k. gv is an X front-end for the Ghostscript PostScript(TM) interpreter.
• okular - Install okular - KDE pdf viewer, requires many KDE prerequisites. Can easily copy text and images.
• acroread - Adobe Acrobat Reader, no longer supported for Linux by Adobe, seems to be no longer supported by Ubuntu.
• qpdfview
• Installation
• open terminal and type the following commands

sudo add-apt-repository ppa:b-eltzner/qpdfview
sudo apt-get update
sudo apt-get install qpdfview

•  Xournal
  By far this one is the best
• Installation
• Open terminal and type the following commands

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install xournal
Optional, to remove xournal, do:

 sudo apt-get remove xournal