The ???Cahiers???have been created by Charles Ehresmann in 1957/58. We have decided to make an important change on their 60th birthday: from January 2018 on, the ???Cahiers??? will become a free (and no-fee) Open Access Journal (no longer paper-printed), while keeping their present objectives and presentation (except for paper being replaced by e-file). Indeed, the volume of each year will still consist of 4 quarterly issues (about 80-100 pages each), in the same format as the present Cahiers except that they will be pdf files rather than paper-books. At the beginning of each quarter, the (entire) corresponding issue will be posted on the site http://ehres.pagesperso-orange.fr/Cahiers/Ctgdc.htm and will be freely downloadable. The people who ask for it will be informed when an issue is published online and downloadable. And the separate articles will also be freely downloadable from the Louvain-la-Neuve mirror site (which is almost ready, and will be functional soon). There will still be no charge for authors nor their institution. We hope this change toward more modernity and easier access will allow for more permanency of the ???Cahiers???, and an increased visibility. Andree Ehresmann, Marino Gran and Rene Guitart [For admin and other information see: http://www.mta.ca/~cat-dist/ ]