In the recent decades robotic and computer science have been gaining more and more relevance in all aspects of our lives. In surgery, for example, they gave birth to procedures that would be impossible to perform otherwise (e.g. tele-surgery, nano-surgery). On this regard, these applied sciences already play an important role in assisting the surgeon both in the operative room and as a support in the education of young surgeons, but much work has still to be done. This paper presents some research and applicative results on Computer Assisted Surgery achieved in the framework of Endocas, a newly founded Center of Excellence in Pisa: A method for segmentation of anatomic parts from 3D dataset able to recover shapes from noisy 3D dataset; A technique for simulating bone drilling using a adaptive decomposition of tetrahedral meshes; A new open source library to support the implementation of techniques for simulating deformable objects.