Strongly agree -- I'm on a team at Facebook that has D code in production. There is a lot of investment that we'd have to do to make it what I'd call solidly pr

Strongly agree -- I'm on a team at Facebook that has D code in production. There is a lot of investment that we'd have to do to make it what I'd call solidly production quality. At one point, I found myself writing a heap profiler, since the tools available where inadequate. If your company doesn't have the ability or will to fix issues deep within the runtime of the shiny new system you're using, I'd be cautious about using a shiny new tool in production. I'm not necessarily saying "Don't do it", but you do need to think long and hard about how you'd handle a tricky bug in your tool.