[jordigh]

D's compiler was never "closed source" if by that you mean "source not visible". It had a weird non-open source license for a long time, but the source has always been visible.

The weird license did use to scare me away, but that's very much a thing of the past now and now it has a standard free license.

https://news.ycombinator.com/item?id=14060846

I don't think D's features are any less exciting than Rust's, but Rust has had a lot of RESF backed by Mozilla.

[ryan_lane]

Source code being visible doesn't make it open source. It had a personal-use-only license, which isn't a valid OSSI license (which is what makes something open source).

[jordigh]

That's why I qualified it with "if that's what you mean by closed source". I don't know if all source is either open or closed and anything that isn't OSI-approved is closed. I don't think that's what people usually mean by "closed source".

I also freely granted that dmd's ad-hoc license wasn't open source despite having visible source.