Audio&Slides
Hermitian forms and quadratic forms, positive and negative hermitian K-theory, various versions of the periodicity theorem, homotopy invariance, topological analogs, the case when 2 is not invertible, a new homology theory on rings : the stabilized Witt group.

Reading list :
M. Karoubi et O. Villamayor : K-théorie algébrique et K-théorie topologique II. Math. Scand. 32, p. 57-86 (1973).
A. Bak : K-theory of forms. Annals of Math. Studies 98. Princeton University Press (1981).
M. Karoubi : Théorie de Quillen et homologie du groupe orthogonal. Le théorème fondamental de la K-théorie hermitienne. Annals of Math. 112, p. 207-282 (1980).
F.J-B.J Clauwens : the K-theory of almost hermitian forms. Topological structures II, Mathematical Centre Tracts 115, p. 41-49 (1979).
M. Karoubi : stabilization of the Witt group. C.R. Math. Acad. Sci. Paris 342, p. 165-168 (2006)