The open source x86_64 emulation layer Box64 just shipped version 0.4.2, and the headline feature is one few people saw coming: an initial PPC64LE back-end that lets users run Linux games and x86_64 binaries on IBM POWER and OpenPOWER systems. The back-end is not yet complete, but it is already functional enough to be usable, marking the project's most architecturally ambitious expansion yet. Box64 now targets four non-x86 architectures, with existing support for AArch64 and experimental work on RISC-V RV64 and LoongArch.
Steam compatibility gets a significant boost in this release as well. Box64 0.4.2 adds support for Steam Runtime 3 (SteamRT3) and Proton 11.0, the recently released beta of Valve's Wine-based compatibility layer for running Windows games on Linux. The project has also begun implementing Vulkan x64 overlay support, which means Steam's overlay, Fossilize, and GameOverlayUI should start working properly under Box64 in the near future.
While Valve-sponsored FEX-Emu has drawn attention for its role in the upcoming Steam Frame headset, Box64 continues to carve out a broader niche by targeting multiple CPU architectures rather than focusing solely on ARM. For anyone running Linux on non-x86 hardware, whether that is an ARM single-board computer, a RISC-V development board, or an OpenPOWER workstation, Box64 remains one of the most versatile tools for bridging the x86_64 software gap.