About alternatives to Matlab

[Beliavsky]

I came across SAGE "Software for Algebra and Geometry Experimentation"
http://sage.math.washington.edu/sage/ , which includes Python and
Numeric and consists of

Group theory and combinatorics -- GAP
Symbolic computation and Calculus -- Maxima
Commutative algebra -- Singular
Number theory  -- PARI, MWRANK, NTL
Graphics -- Matplotlib
Numerical methods -- GSL and Numeric
Mainstream programming language -- Python
Interactive shell -- IPython
Graphical User Interface -- The SAGE Notebook
Versioned Source Tracking -- Mercurial HG

Maybe people who has tried this could give their impressions.