Hi, there's been some movement forward on the Single User Login (SUL) issue. I ask the Board to review this mail carefully as this has significant long- term implications and we need Board input to go ahead. I also ask other developers to correct me if I misrepresent anything. There are currently three competing strategies. Before I describe these strategies, let me point out that one important consideration for any system is scalability. That is, single login will be used on all existing and future Wikimedia projects, and potentially even on non-Wikimedia sites which we allow to participate in our system. The three strategies are: 1) GLOBAL NAMESPACE, IMMEDIATE CONFLICT RESOLUTION We try to move towards a single global user namespace for all Wikimedia wikis. If a name is already taken in the global namespace, you have to find one which isn't. For the migration, any names which clearly belong to the same user are combined into one. If passwords and email addresses are different, the user can manually link together any accounts which belong to him by providing the passwords. For cases of true name conflicts between the existing wikis, there is a resolution phase, where factors like seniority, use on multiple wikis vs. a single one, etc., are weighed in - the "loser" has to choose a new account name. After the manual resolution phase, any remaining accounts are converted to the new system automatically by making them unique, e.g. by adding a number to the username. The transition is now complete. The old system no longer exists.

1) is very complex, and we may not find someone willing to deal with the name conflict resolution issue and take the blame from annoyed users at the same time. Naming conflicts will always be an issue in this scheme, as e.g. all common first names will be taken, and any small wiki hooking up with our SUL system would feel this impact. People can mutate these usernames relatively easily to make them unique - Erik333 - and the system can offer such mutations, but it's still a bit annoying.