I won't claim this is a very good solution, but the built-in picture can be used for this. I did use graphicx for \rotatebox though.

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\setlength\unitlength{1cm}
\begin{picture}(4,4)
\multiput(0.1,0.1)(0,1){4}{\line(1,0){3}}
\multiput(0.1,0.1)(1,0){4}{\line(0,1){3}}
\put(0.5,0.5){1}
\put(1.5,0.5){2}
\put(2.5,0.5){3}
\put(0.5,1.5){4}
\put(1.5,1.5){5}
\put(2.5,1.5){6}
\put(0.5,2.5){7}
\put(1.5,2.5){8}
\put(2.5,2.5){9}
\put(-0.5,2.5){A}
\put(-0.5,1.5){B}
\put(-0.5,0.5){C}
\put(0.5,3.5){A}
\put(1.5,3.5){B}
\put(2.5,3.5){C}
\put (-1.2,1.5){\rotatebox{90}{Text}}
\put(1.2,4.2){Text}
\end{picture}
\end{document}
correlation matrix? – Oct 06 '15 at 16:11xcolor,graphicx, andstackengine, but nottikz. – Steven B. Segletes Oct 06 '15 at 16:22