D 2.067.0 is out and comes with a much faster GC for most applications. We’re seeing speedups of roughly 30% for GC heavy applications, with a slightly increase in memory consumption.

I recently gave a presentation about the improvements at the Berlin D meetup, slides are here.

As announced in the changelog the two most important improvements are a better grow strategy and a faster tail-recursive marking, more details will follow soon. This work was complemented by many refactorings and a better benchmark suite.