It's not that you don't have to know or worry about groundbreaking projects like Zing, but that they don't exist. The resources put into advancing the Erlang ecosystem are a tiny fraction of those put into the JVM ecosystem, and it shows.
You say BEAM "just works", but it "just works" if you can put up with its non-stellar performance or happen to play directly to its strengths. Any technology just works if you happen to need exactly what it provides. Java and the JVM, however, like the Linux kernel, are a huge project with vast resources, wide reach and very wide applicability from small embedded devices to mainframes. So, naturally, there are a lot of things to choose from, but you are guaranteed to find one that suits your need -- no matter what it is.
Too many Erlang projects start out thinking Erlang is good enough, and then find that they need to write more and more of their code in C. This just cannot happen with the JVM. Not that it's appropriate for everything (it's bad for command-line utilities and Java SE is inappropriate for constrained environments), but it's much harder to miss. You don't need to know or worry about Zing unless you need what it provides (worst-case latency of under 50us); similarly for other tens of thousands of JVM libraries and tools. All you need to know is that you can find a high-quality implementation of whatever you might need down the line.
As for Zing's source code: Zing is proprietary, but as the JVM ecosystem is so big, there's a similar open-source attempt by Red Hat and intended to go into OpenJDK called Shenandoah[1]. Its code is here: http://icedtea.classpath.org/hg/jdk9-shenandoah/hotspot/
You say BEAM "just works", but it "just works" if you can put up with its non-stellar performance or happen to play directly to its strengths. Any technology just works if you happen to need exactly what it provides. Java and the JVM, however, like the Linux kernel, are a huge project with vast resources, wide reach and very wide applicability from small embedded devices to mainframes. So, naturally, there are a lot of things to choose from, but you are guaranteed to find one that suits your need -- no matter what it is.
Too many Erlang projects start out thinking Erlang is good enough, and then find that they need to write more and more of their code in C. This just cannot happen with the JVM. Not that it's appropriate for everything (it's bad for command-line utilities and Java SE is inappropriate for constrained environments), but it's much harder to miss. You don't need to know or worry about Zing unless you need what it provides (worst-case latency of under 50us); similarly for other tens of thousands of JVM libraries and tools. All you need to know is that you can find a high-quality implementation of whatever you might need down the line.
As for Zing's source code: Zing is proprietary, but as the JVM ecosystem is so big, there's a similar open-source attempt by Red Hat and intended to go into OpenJDK called Shenandoah[1]. Its code is here: http://icedtea.classpath.org/hg/jdk9-shenandoah/hotspot/
[1]: http://openjdk.java.net/jeps/189