cubicweb-semnews #2934552 Talk about open source, forking and reporting bug in about page [open]

mention everything is opensource in http://demo.cubicweb.org/semnews/doc/about

Have a footer like : Fork me linking to http://hg.logilab.org/master/cubes/semnews

prioritynormal
typeenhancement
done in<not specified>
closed by<not specified>