This is not a security question.  Please ask in a solaris newsgroup instead,
or ask someone near you because it's a detail, and easy to diagnose in
person but sometimes hard to diagnose over the net (depending on the problem).

If you get the message "language optional software package not installed",
this means that the compiler is not installed.  (Like, duh.)  Sun doesn't
include a C compiler with Solaris.  Get gcc.  Put it in your path and/or in
the makefile (e.g. CC=gcc).  Perhaps do "ln -s gcc /usr/local/bin/cc" so that
/usr/local/bin/cc points to /usr/local/bin/gcc, and make sure /usr/local/bin
is near the front of your path.  This is still not a security question.

If you are using the Sun compiler tools, or having problems with other missing
commands such as "make" or "ar", perhaps you need to add /usr/ccs/bin to
your path.  This is not a security question either.