We discuss a new covariant approach to geometry, called conformal geometric algebra, concentrating particularly on applications to projective geometry and new hybrid geometries. In addition, a new method of working, which can achieve similar results, but using only one extra dimension instead of two, is also discussed.
Anthony Lasenby, Recent Applications of Conformal Geometric Algebra, H. Li, P. J. Olver and G. Sommer (Eds.): IWMM 2004, LNCS 3519 Springer-Verlag (2005)