Dear category theorists, Here is an annoucement of preprint. URL : http://www-irma.u-strasbg.fr/~gaucher/multi_en.ps.gz or http://www-irma.u-strasbg.fr/irma/publications/1999/99010.shtml Title : Homotopy invariants of multiple categories and concurrency in computer science Abstract : We associate to any (strict) multiple category $\C$ three homology theories : the first one is called the globular homology and it contains the oriented loops of $\C$ ; both other ones are called corner homology, the negative one and the positive one, which contain the corners included in $\C$. We show up the link between this homology theories and the homotopy of paths in multiple category. At the end of the paper, we explain the reason why this theories are interesting for some geometric problems coming from computer science.