Quote - Good luck with your software, im looking forward to it. (ill go at sourcefourge when i`m back home)

Thanks :).
I found this about ProEngineer (http://en.wikipedia.org/wiki/ProEngineer) and this (http://en.wikipedia.org/wiki/Parametric_feature_based_modeler) :
" Parametric feature based modelers use change states to maintain information about building the model and use Lisp expressions to constrain associations between the constructive solid geometries. "
It seems that it has some interesting features related to the mathematical modeling...however, apparently it's using an  internal representation of it's objects so I can't tell if it's a "pure" mathematical modeler (in the sense that a mathematical description can be put down in a paper)!
A mathematical object is nothing more than a set of a mathematical fuctions along with the limits where they are defined so, for me, the purpose of a mathematical modeler is to generate this mathematical description. Also, there is a lot of mathematical reprentations (parametrique, iso, minimal...) and the quality of mathematical modeler may depend on how many of theses methods it uses and how it did it : K3DSurf for instance uses two techniques (Parametric and Iso).
To resume, a mathematical modeler is a "functions generator" rather than an "object generator". In fact, every object we can think about IS a mathematical object, knowing it's mathematical description is another story... We can do some mathematical modeling by taking some easy mathematical object (sphere, cube,...) and rise there complexitys by applying some simple transformations( this is what I'm calling "Morph effect") or construct theme from a low level mathematical object (example : surface generation from curves in "Carrara studio", "http://www.3dvf.com/modules/publish/Logiciels_259_1.html",  thanks SHONNER) ...
K3DSurf is trying to implement some of theses technics but as I sayed before, the way is still long but I hope at least to catch the interest of some of you ;-)
Taha