If you are looking for a free software clone of Matlab (numerical matrix computation), give a try to GNU Octave/QtOctave or to FreeMat or to Scilab. If you are looking for a free software clone of Maple (computer algebra system), give a try to Giac/Xcas or to Maxima/wxMaxima. You may also take a look at SAGE. If you are looking for a free software clone of S-Plus (statistical data analysis and graphical representation), give a try to GNU R. If you want to install GNU/Linux on your desktop or laptop computer, try Ubuntu, which is based on Debian GNU/Linux. If your laptop is a MacBook, you may also take a look at the MacBook Ubuntu Community Documentation. If you like Unix but feel that GNU/Linux is too gregarious, give a try to FreeBSD (powers Mac OS X).