Show HN: RunMat – runtime with auto CPU/GPU routing for dense math

Summary

🚀 RunMat: The fastest runtime for your math RunMat automatically fuses operations and intelligently routes between CPU and GPU. MATLAB syntax. No kernel code, no rewrites. 🌐 Website • 📖 Documentation RunMat is an early build. The core runtime and GPU engine already pass thousands of tests, but some plotting features are still missing or buggy. Expect a few rough edges. Feedback and bug reports help us decide what to fix next. What is RunMat? With RunMat you write your math in clean, readable MATLAB-style syntax. RunMat automatically fuses your operations into optimized kernels and runs them on the best place — CPU or GPU. On GPU, it can often match or beat hand-tuned CUDA on many dense numerical workloads It runs on whatever GPU you have — NVIDIA, AMD, Apple Silicon, Intel — through native APIs (Metal / DirectX 12 / Vulkan). No device management. No vendor lock-in. No rewrites. Core ideas: MATLAB syntax, not a new language Fast on CPU and GPU , with one runtime , with one runtime No device flags — Fusion automatically chooses CPU vs GPU based on data size and transfer cost heuristics ✨ Features at a glance MATLAB language Familiar .m files, arrays, control flow Many MATLAB / Octave scripts run with few or no changes Fusion: automatic CPU+GPU choice Builds an internal graph of array ops Fuses elementwise ops and reductions into bigger kernels Chooses CPU or GPU per kernel based on shape and transfer cost Keeps arrays on device when that is faster Modern CPU runtime Ignition interpreter for fast startup Turbine JIT (Cranelift) for hot paths Generational GC tuned for numeric code Memory-safe by design (Rust) Cross-platform GPU backend Uses wgpu / WebGPU Supports Metal (macOS), DirectX 12 (Windows), Vulkan (Linux) Falls back to CPU when workloads are too small for GPU to win Plotting and tooling (pre-release) Simple 2D line and scatter plots work today Plots that use filled shapes or meshes (box plots, violin plots, surfaces, many 3D views) are not wired up yet 3D plots...