This version of Tic-Tac-Toe is written in Common Lisp.
For the best experience, you are encouraged to use Mac OS X or a Linux distro and install SBCL (Steel Bank Common Lisp).

Many distros package sbcl but if yours doesn't or you're on OS X you'll want to check out http://www.sbcl.org/.
Once SBCL is installed and in your PATH, you should be able to cd to the lisp source directory and run ./tic-tac-toe.

If for some reason it doesn't work, ensure that running "sbcl" in the terminal brings up the Lisp prompt and try running chmod +x tic-tac-toe to ensure the script has execute permissions.