I currently work on one of the most trafficked production Derby applications[0] and I must say that this is a very welcome change. Derby's creators have time and time again proven that they care about the nodejs ecosystem. By funding ShareJS's development, they're ensuring that an unbelievable tool (simplified OT) will be sticking around for quite some time. Writing code with Derby has been far and away the most pleasant development experience I have ever had.

If there's been one issue with Derby so far, it's been Racer. The data sync-ing engine leaks memory and is largely unstable. We've suffered far too much downtime due to these issues. Moving to a fresh backend with ShareJS enables Nate, Brian, Joseph and the rest of the team to rework the scope of the framework with some of the larger goals in mind – things like horizontal scaling and powerful conflict resolution. We have yet to upgrade to 0.5 (the upgrade guide was literally just released), but it appears to be a much more stable foundation on which to build a "real-time" web application. I'm sure we'll have to put up with bugs for quite a few weeks, but this is a powerful step towards reaching 1.0. Thanks guys!

[0] https://habitrpg.com (source: http://github.com/lefnire/habitrpg)