Thanks for pointing to that, it's super interesting. One of the things we designed Dark around was being able to safely and easily continuously deliver languag

Thanks for pointing to that, it's super interesting. One of the things we designed Dark around was being able to safely and easily continuously deliver language and framework changes. The Zope 3 project was a disaster by the sound of it, and I would hope this will allow us avoid a similar fate. That's the goal. Also, we're pretty pro-testing (though also type systems, which help too).