Hello Battery,
if a program is not part of the repositories, the next step is to look up
whether there is somewhere a .deb file or not.
Another option is using a ppa;
perhaps you can search for something like "peerguardian ubuntu" or something
similiar, and perhaps you will find a ppa (i.e. a seperate source for the
packet managment system) ; be aware of ppas with proprietary software. But if
you install only the free program, there should be no danger of using
proprietary software.
Last option is to compile the program. It's really an exception. During
normal computing, this is not necessary.
Before compiling, you should make sure that you have the build-essential and
g++ installed.
With your program, a
sh autogen.sh
autoreconf
./configure
make
sudo make install
should do the trick. Precondition is you have downloaded the source code.
git clone git://peerguardian.git.sourceforge.net/gitroot/peerguardian/peerg
uardian
You need git installed for this:
sudo apt-get install git.