nefuOS: A from-scratch OS with a browser, WebGL, and a local LLM — built in one month

One month ago, I saw someone's hobby OS and thought: "I want to build one too." One month later, nefuOS runs a browser, a compiler, a package manager, and a local LLM. nefuOS is a full OS stack written from scratch: Ncore — custom kernel, boots via both BIOS (El Torito) and UEFI (GRUB multiboot2) Nbrower — custom browser with HTML/CSS/JS/WebGL2, own TLS 1.3 stack nefucpp — C++ → .nefud compiler NPKG — package manager over HTTPS, installs .deb-style packages Nshell — 60+ Unix-like commands Ngame — 34 built-in games NAI — a fine-tuned Qwen2.5-1.5B that actually calls tools (writes files, runs commands) Chinese IME, TTF rendering, 107 built-in apps This was the interesting part. I hand-wrote the first ~120k lines (kernel, VFS, IPC, the core architecture). Then I let AI fill in the implementation details — about 80% of the rest. Architecture, decisions, and debugging are mine. AI just made the typing faster. Self-developed: ~215k lines (C/C++ ~192k, Python ~24k) With third-party: ~1.04M lines One month BIOS + UEFI dual boot — same kernel, two boot paths, one codebase TLS 1.3 from scratch — for the browser to talk to real sites QuickJS 2021 bugs — the old build crashes on a second JS_Eval; had to work around it SWGL — 9000 lines of software GL, needed to run WebGL2 without a GPU driver bloxd.io WebGL rendering (canvas pipeline is almost there) Better CSS support (flexbox, descendant selectors) DeepSeek login fully wired into the browser GitHub: https://github.com/Nefu-Dev/nefuOS Happy to answer questions about the architecture, the AI-assisted workflow, or the dual-backend design.