I'm following the instructions on the MTT setup page.
Would someone clarify the <your dir> parameters below.
PREFIX is logically (to me) "where I am putting MTT" , yes?
But LIB is always confusing.  Is this some MPI lib directory,
a perl library or the same as <your dir> above - where I am putting MTT. 
And if so, how do I find where those happen
to reside?
Pointing PERLLIB means setting the env var, right?
New to this, thanks.,
If you do not have root access:

$ perl Makefile.PL LIB=<your dir> PREFIX=<your dir>
$ make
$ make install

You will then need to point PERLLIB to <your dir> to run MTT.