Mestre's paper:  http://www.aimath.org/~farmer/print/mestre_explicit.pdf

Mathematica notebook that implements the explicit formula:  http://www.aimath.org/~farmer/print/explicit_formula_demo1b.nb


PDF of Mathematica notebook:  http://www.aimath.org/~farmer/print/explicit_formula_demo1b.pdf

Sage worksheet that implements the explicit formula [[attachment:explicit_formula_demo.sws]].  Much more user friendly and actually correct!

Another sage file that has some explicit formula stuff, specific for elliptic curves [[attachment:explicit_formula.sage]]