One of the all time great SNL skits featuring the late great Chris Farley.

How do I find out what version of Linux I'm using?

lsb_release -d

Also...
uname -a
or...
cat /etc/issue
or...
cat /etc/*-release

What version of Python am I using?
python -V

What version of MySQL am I using?
within MySQL, do:
select version();

external from MySQL do:
mysql -V

How Do I Determine What Version of Perl I'm Using?
perl -v

To find out the versions of each module, do:
perldoc -t perllocal

For the version of Perl Doc you're using:
perldoc -V

POD is the Plain Old Documentation format.