Sverchok - is parametric tool for an architect, designer, lets you to programm object's form without knowing program longuages.
It is addon to blender
Lets you operate with digits and math with height level language - visual nodes.
Sverchok IS parametric tool for generating geometry.
Sverchok IS NOT all-in-nodes tools of blender. It not have to have particles, lighting and so on.
Main developing line: MATH + MESH + SPLINES + NURBS.
Those who familiar with Houdini or Rhinoceros 3D might know the visual scripting language Grasshopper, which Sverchok has been inspired by. Using a similar node based visual programming principle, we trying to bring this functionality to Blender users.
To understand what is parametric in ARCHITECTURE you'd see here.