Sage and Mathematica are both very powerful mathematics tools. For an absolute beginner both packages will do, I suppose.
Mathematica is closed source and for the price of a full edition Mathematica package you can also buy a state-of-the-art Sony VAIO or other sexy netbook or tablet you are thinking of buying. The Mathematica programming language is a so called propriety language. That means that it is only used in Mathematica and the owners of Mathematica can change the language whenever they want. Mathematica has a steep learning curve. Now that I master the basics of it I am very satisfied with what Mathematica can do for me.
Because Sage says it is possible to integrate Mathematica into Sage ( haven't figured yet out how, I suppose I need the Mathematica for Linux version ) I am having another look at Sage. Sage is Linux only but you can run it entirely from within a browser. So you can install Sage on a Linux server ( for example in a VMWare virtual machine ) and run it on Windows in your browser.
( More later about my Sage findings. )
13-2016 Open letter to Open Source for You (OSFY)
4 months ago