On 06 Jun 2015, at 09:26, abdelghani ALIDRA <alidrandco@yahoo.fr> wrote:Hi Guys,I believe the Ring metamodel has been proposed 4 or 5 years earlier.Is it acctually in use in the current pharo tools? which ones?I have been told that Martin has develloped a different model : FicusWhat are the limitations that Martin tried to fixed?What can be further unhanced?Thanks.Abdou.