Rhinoceros (also known as Rhino) program for designing and modeling 3D objects is one of the best tools for solid modeling and visualization. The program is based on modern NURBS  technology and allows to create precise objects using a relatively small system resources.
Rhinoceros is widely used in many fields and industries. Capabilities can be enhanced by installing extensions for architects, that automates and simplifies the design process.
Rhino supports SPLOP and UDT (Universal Deformation Technology) and has the ability to extend the functionality of an additional rendering engines. The program is relatively easy to use and intuitive. It supports more than 30 different formats, including DWG, DXF, OBJ and 3DS.
And last but not least – Rhino has good price/performance ratio.