[gunnarmorling]

Unless you are on a realtime OS, you may see longer pauses from the OS due to scheduling other processes, so I think it's fair to consider the new low-latency collectors (Shenandoah, ZGC) pauseless from a practical point of view.

[pebal]

You can't call GC pauseless if it introduces pauses. We don't say something is free if you have to pay little for it. We say it's cheap.

[adambatkin]

I think as a technical term, pausless (as used here) has a specific meaning, just like real-time has a specific technical meaning (not literally 0 latency since that's generally physically impossible).