Concurrent GC is not currently planned, but it should be noted that our generational GC does wonders to reduce GC pause time anyway. Additionally, even Hotspot

Concurrent GC is not currently planned, but it should be noted that our generational GC does wonders to reduce GC pause time anyway. Additionally, even Hotspot typically defaults to their stop-the-world GC. This is because a concurrent GC typically spreads part of the GC time around, ie, performance is slower to reduced GC pause time. But even a concurrent GC typically has to stop all threads at some point to get everything consistent.