I think the revealing term here is 'implicit promise'. A lot of people seem to have very fixed expectations about how open source projects should be run, and fe

I think the revealing term here is 'implicit promise'. A lot of people seem to have very fixed expectations about how open source projects should be run, and feel that they've been betrayed if a project isn't run in that way. I don't think Evan is to blame for that, though. The bottom line is that no project that's run by one person in their free time is able to give assurances of anything over the long term. I do think that if half of Evan's critics had the experience of running a reasonably popular open source project, they'd realize how meaningless any long-term 'assurance' is. I'm not sure what you're referring to when you say that Evan broke everyone's code. I was writing Elm code as part of my day job during the 0.18-0.19 transition, and it was not particularly painful. But this is all by the by. The fundamental question is the following. How would you propose to keep Elm pure while still allowing community libraries to access the FFI?