On Stack Replacement, for optimizing hot loops on the fly. Improved inlining and dead code elimination. Native calling improvements, with pointer manipulation and casts. Significant improvements to string performance in a number of use cases. Asynchrony and threading bug fixes. And more!
Short for "Metamodel On A Runtime", MoarVM is a virtual machine built especially for Rakudo Perl 6 and the NQP Compiler Toolchain. While still being under very active development, MoarVM already stands out amongst the various Rakudo and NQP compilation targets by typically:
For long-running workloads where startup time doesn't matter, or when you need tried-and-tested, mature threading support, Rakudo on the JVM is a better bet; its JIT compiler gets to work and makes quite a difference. For maximum module coverage, Rakudo on Parrot may have a small edge, but that is changing fast.