Expert Answer:
s:
.mat files contain binary data, so you will not be able to open them easily with a word processor. There are some options for opening them outside of MATLAB:
If all you need to do is look at the files, you could obtain Octave, which is a free, but somewhat slower implementation of MATLAB. You can refer to How do you open .mat files in Octave? for more information on the subject. You can get octave from http://www.gnu.org/software/octave/download.html. The interface is very similar to MATLAB's.
As NKN and Ergodicity mentioned, there are python libaries available for this as well.