iMathGeo is a powerful software which allows you to produce mathematical documents with a typographical quality, to communicate with many softwares (Indesign, Word, Keynote, Pages, etc …), to do formal calculation and basic dynamic geometry.
Here's a "little" presentation of this software ...
Formal calculation :

You can :
- working with big numbers.
- enter your mathematical formulas and transform them so that they are to simplify to the maximum.
- make symbolic algebraic calculation.
- make substitutions.
- differential calculation.
- make factorizations.
- substitution with the "Eval" function.
- solving equations and in equation
- working with matrices (eigen vectors search, inverse a symbolic matrix, etc....).
- Statistics (with mean, correlation, variance, etc ....)
- etc....
Through services technology, it's possible to do formal calculation under other softwares like "Numbers", "Pages", etc ...