We are not yet up to Facebook power at weka.io but we fully use D and support some development of it. We have also released recently a library we use internally for user space threads and other support stuff, called mecca.
D is really nice and very effective, even for a soft real-time system like ours. Most of our code didn't do any GC but where we don't care too much we can make our life a little easier.
D is really nice and very effective, even for a soft real-time system like ours. Most of our code didn't do any GC but where we don't care too much we can make our life a little easier.