v3 is still pretty good though. I was hoping that some eager people would fork it to keep it going, but it looks like the interest is smaller than I hoped. Maybe I'll pick it up myself one day.

The core of ServiceStack (services, messages, routes; that part) is so well designed that I simply refuse giving up on it. I think that if I were to use a different language for whatever project, I'd probably rather spend many evenings reimplementing those core concepts than going with something less good (such as the common one-method-call per URL pattern of MVC WebAPI, Rails controllers, Sinatra, Flask, etc etc etc).

I'd probably buy ServiceStack v4 if it wasn't so outrageously expensive.