[http://www.gnome.org/projects/evince/ Evince] is a GTK+ PDF and PS viewer. Using mozplugger you can embed it into Mozilla and/or Firefox.
First make sure you have Evince and mozplugger installed, otherwise isntall with:
sudo apt-get install evince mozplugger
Now edit /etc/mozpluggerrc.
sudo gedit /etc/mozpluggerrc
Look for these lines:
application/pdf: pdf: PDF file application/x-pdf: pdf: PDF file text/pdf: pdf: PDF file text/x-pdf: pdf: PDF file
and these lines:
application/x-postscript: ps: PostScript file application/postscript: ps: PostScript file
then add the following line beloew them:
repeat noisy swallow(evince) fill: evince "$file"
Example:
application/pdf: pdf: PDF file application/x-pdf: pdf: PDF file text/pdf: pdf: PDF file text/x-pdf: pdf: PDF file repeat noisy swallow(evince) fill: evince "$file" repeat swallow(acrobatreader) fill: acroread -geometry +9000+9000 +useFrontEndProgram -tempFileTitle acrobatreader "$file" repeat noisy swallow(win) fill: xpdf -g +9000+9000 "$file" repeat noisy swallow(gv) fill: gv -safer -quiet -antialias -geometry +9000+9000 "$file" application/x-postscript: ps: PostScript file application/postscript: ps: PostScript file repeat noisy swallow(evince) fill: evince "$file" repeat noisy swallow(gv) fill: gv -safer -quiet -antialias -geometry +9000+9000 "$file" repeat swallow(Pageview) fill: pageview "$file"
Credits: [http://ubuntuforums.org/showthread.php?t=25685&page=1&pp=10 Saik0]