NEO Emacs

Emacs, rewritten in Rust — unleashed on the GPU, fixing what 40 years of C never could. Built for 100% compatibility with the Emacs ecosystem you already have — your config, your packages, your muscle memory.

NEO Emacs keeps everything that makes Emacs Emacs — your init.el, your packages, your muscle memory — and rebuilds the machinery underneath: the display engine runs on the GPU, and the ~300,000-line C core is reimplemented in Rust. GNU Emacs itself serves as the test oracle, so every rewritten subsystem is verified to behave identically.

Highlights:

• GPU display engine — text, images, and effects rendered via wgpu (Vulkan · Metal · DX12 · GL); ~4,000 lines of Rust replace ~50,000 lines of xdisp.c
• Rich media in buffers — inline 4K video (typed Rust GStreamer + VA-API integration on Linux), GPU-decoded images, a WPE WebKit browser, and a GPU terminal; DMA-BUF paths stay on the GPU, with typed fallbacks where native interop is unavailable
• Animations everywhere — 8 cursor modes, 21 scroll effects, 10 buffer transitions at display refresh rate, all configurable from Elisp (full catalog)
• Hackable below the Lisp line — in GNU Emacs, hackability ends where the C display engine begins; NEO Emacs opens the whole frontend to Elisp, from render effects down to GPU shaders (WGSL) — hack the pixels, not just the text
• Compatibility as the contract — your init.el, packages, and muscle memory; every rewritten subsystem is diffed against GNU Emacs as a test oracle, and real-world configs like Doom Emacs are the daily test bed
• Pure-Rust core — no C left: the Elisp evaluator, bytecode VM, GC, portable dump, and editor internals are all memory-safe, modern Rust
• GUI or terminal — the same binary renders on the GPU or in a TTY (neomacs -nw)
• What's next — true multi-threaded Elisp and a concurrent zero-pause GC (status)