Help installing a java plugin, using make.

[leegold at speedymail.org]

Hi,

I need some newbie help with "make" - manually installing a java plugin
for Firefox 3.6.x. I got some help from one of the developers of the
icetea java plugin. I want to be sure I understand what he's saying on
how to install. Here's the instructions:

"You'll need to build your own version of IcedTea-Web:

http://dbhole.wordpress.com/2011/07/20/icedtea-web-1-0-4-and-1-1-1-security-releases-released/

against the Firefox installed in /opt which uses xulrunner 1.9.  The
version
with 4 & 5 will use xulrunner 2 and so presumably won't work with FF
3.6.x.

I imagine you'll need to set PKG_CONFIG_PATH to the location of the *.pc
files in your
/opt installed Mozilla so IcedTea-Web's build picks it up."

Questions: 

Build against FF in /opt? My FF is installed in /opt/firefox/. What does
"build against" mean?

PKG_CONFIG_PATH must be an environment variable. I think I want to
record it's current setting. Change it for this particular  install,
then set it back to what it was (?)

Thanks.