K. Hori at MSRI - Orientifolds: An introduction

<BODY> MSRI Streaming Video Series <BR> K. Hori - Orientifolds: An introduction <BR> <center> A PDF version of the lecture notes is available <A HREF="http://www.msri.org/publications/ln/msri/2004/symplecticgeom/hori/1/meta/aux/hori.pdf">here</A>. </center> </BODY>