Well, the JVM has several GCs they have a lot more potential for tuning, and there are many tools to gather data on what the GC is doing and to analyse heap dum

Well, the JVM has several GCs they have a lot more potential for tuning, and there are many tools to gather data on what the GC is doing and to analyse heap dumps to discover the cause of problems. If you have a language like Ruby which is normally used without a moving GC then there isn’t huge scope for tuning things, but if you have a moving GC then there is a lot you can tinker with regarding region sizes etc.