Other tracing collectors have certainly caught up since 1998, but I'd keep my eye on two things that have also happened since 1998: 1. Work by Damien Doligez w

Other tracing collectors have certainly caught up since 1998, but I'd keep my eye on two things that have also happened since 1998: 1. Work by Damien Doligez which made further improvements to OCaml's current tracing collector (in 4.03) which further reduced pause times. 2. The multicore OCaml tracing collector work that's going on right now at Cambridge. If I understand correctly, this work involved not only partitioning memory into multiple thread local heaps, and a shared heap, but it also improved the collector in general. I haven't tested it but I'm curious if the combination of this work will again put it ahead of other alternatives.