Is there a BNF online for Mathematica? I know there is a project to do Mathematica-like things (computer algebra system) on github written in pure Python ( ht

Is there a BNF online for Mathematica? I know there is a project to do Mathematica-like things (computer algebra system) on github written in pure Python ( http://sympy.org/ http://sympy.org/ ). I've been told that Sage ( http://sagemath.org/ http://sagemath.org/ ) is Mathematica-like but uses Python as its programming language. There is also Maxima ( http://maxima.sourceforge.net/ http://maxima.sourceforge.net/ ) which also has a close to Mathematica experience.