koff3

I would not do this unless there is a use case. For analysis purposes you can always read the whole change history from audit logs. The solution also only gives you the timestamp when something was set, but not when it was unset.

There is also http://www.chesspresso.org/ which worked great for PGN and FEN processing.

I like D a lot but find it's not a good fit for many things. C++, Java and Python have great tools and libraries to rely on. Not so much with D's small community. Writing wrappers and interop always feels like a hassle, so it's easier to stick with just one language.

First time I used D was before the version 2, back when there was the Tango library. D seems to have improved quite a bit since then, but it's still in the same position as before.