Concerning general literature on algorithmic composition and spectral music consider the following book. It contains a nicely detailed article by Rozalie Hirs on Tristan Murail's use of OpenMusic for a specific composition, which Rozalie wrote while or after she was his pupil.
Hirs, R. & Gilmore, B. (eds.) (2009) Contemporary Compositional Techniques and OpenMusic. Collection Musique/Sciences. IRCAM/Delatour.