Jacob Quinn has a translation to Julia here: https://github.com/quinnj/Ryu.jl
Is Ryu.jl significantly faster than what's in Base? Is there already an open issue somewhere?
I don't see an issue about it at the moment. I guess we just expect Jacob to PR it at some point. IIRC he also wrote the Grisu implementation that's in Base.
I'm very interested in how detailed and coordinated the Julia team has become regarding the longer term future of Julia. Admirable effort all around.