See <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=11555017" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=11555017</a> Azul&#x27;s Zing is pauseless, never has to do a stop-the-world collection which they say on a JVM takes about a second per GiB.<p>It has threads which concurrently collect as other threads mutate, uses clever VM tricks such as bulk operations with only one TLB invalidation (or at least they did that with an earlier version of the current collector, they couldn&#x27;t get it into the mainline Linux kernel and now use a DLKM).  It&#x27;s the only non-toy currently maintained pauseless&#x2F;concurrent GC that I know of.