Also, be careful. You should read the LICENSE file which tell you if it is
apparently free software. Choosing or not to install free software, you at
least MUST know which kind of software are you installing.
After that, you can read the README file for knowing more about the program
and INSTALL for reading the details of how to install it. Normally, it is
just to open a terminal in the folder created when the .tar.gz was extracted
and run
./configure
for checking dependencies and setting the root where the program will be
installed (just default without other parameters)
make
for compiling, and
sudo make install
for installing it into your system. However, it is possible that the method
was different, so you must always read INSTALL file, or README if it doesn't
exit. It's the way of installing pakages from source code, which is useful
for installing last versions or unsupported packages, but in general there is
a binary package in the trisquel's repository which saves your time, it's
easier, avoids problems and you can be sure that that software is respecting
your freedom without need of inspecting it deeply.