In honour of Jean-Yves Girard on the occasion of his 60th birthday year, a Festschrift will be published as a special issue of Theoretical Computer Science, where the "Linear Logic" paper was published twenty years ago. The Festschrift follows the two events organized in Siena (http://www.unisi.it/eventi/LOGIC/) and in Paris (http://www-lipn.univ-paris13.fr/jyg60/) this year. Submissions for this special issue are welcome from all the participants to the workshops as well as from other contributors. More details at: http://www.pps.jussieu.fr/~laurent/girard60/ The guest editors, Thomas Ehrhard (thomas.ehrhard@pps.jussieu.fr) Claudia Faggian (claudia.faggian@pps.jussieu.fr) Olivier Laurent (olivier.laurent@pps.jussieu.fr)