x86_64 System V AMD64 ABIThe default 64-bit Unix ABI: Linux, macOS, FreeBSD, OpenBSD, NetBSD, illumos.
x86_64 Windows (Microsoft x64) ABIThe 4-register fast-call convention used by every Windows-on-AMD64 binary.
AArch64 AAPCS64The base 64-bit Arm calling standard, with Apple and Microsoft deltas called out.
AArch64 Windows (Windows-on-ARM64)Windows 11 on Snapdragon X / X2 Elite, Surface Pro X lineage, and ARM64EC interop.
RISC-V RV64GCThe general-purpose 64-bit RISC-V baseline plus vector and recent extensions.
WebAssemblyWasm 3.0 (2025) as the stable target, plus WASI Preview 2/3 and the component model.
Other ISAs: PowerPC, MIPS, LoongArch, s390x, Apple GPU/MetalSurvey of niche or specialized architectures that MEP-42 should be aware of but probably defer.
Targets SummarySingle-page roll-up of every (target ISA x OS) combination Mochi MEP-42 could ship, with status and engineering complexity recommendations.