Erlang/OTP and BEAM have been around a long time and is probably just as mature as the JVM and Java, but they have slightly different goals: very low tail laten

Erlang/OTP and BEAM have been around a long time and is probably just as mature as the JVM and Java, but they have slightly different goals: very low tail latency, easy error recovery, and easy distributed compute in erlang vs. better customization and median performance for the JVM. I'm sure there's more differences and more nuance than that, but I'd be very happy to use either language/VM in production.