I'm genuinely surprised that one would say that Julia is "slowing down in development". Perhaps it's because less press is being generated about Julia? Or that the commit rate has gone down slightly, now that the easier issues have been picked off and the remaining work will take longer for the next round of incremental developments? I'm not sure what the OP meant, but from the inside, we are busier than ever.

- Both Julia Computing and the Julia Lab have grown sizably over the past two years. The Lab now houses ten full-time researchers (up from four last year), with five new students coming online over the summer and fall. We also maintain more active research collaborations with more research groups at MIT and off-campus.

- Julia is a grateful recipient of 12 Google Summer of Code slots this year, compared to 8 for 2015's Julia Summer of Code program (sponsored by the Moore Foundation) and 4 for GSoC 2014.

- JuliaCon grew from 72 attendees in 2014 to 225 in 2015 and we are on track to meet or exceed last year's ticket sales for 2016.

- New packages continue to be registered on the central METADATA repository at roughly the same rate since June 2014. http://pkg.julialang.org/pulse.html

By some measures we are still a relatively small project, but I don't see any serious evidence for the imminent heat death of the Julia universe.