The latest articles on DEV Community by nefu-dev (@nefu-dev). https://dev.to/nefu-dev https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4157253%2Fe07d4120-8db3-4399-b2d4-0cdf481b3d0a.png https://dev.to/nefu-dev en nefu-dev Fri, 02 Oct 2026 11:40:17 +0000 https://dev.to/nefu-dev/nefuos-a-from-scratch-os-with-a-browser-webgl-and-a-local-llm-built-in-one-month-l1b https://dev.to/nefu-dev/nefuos-a-from-scratch-os-with-a-browser-webgl-and-a-local-llm-built-in-one-month-l1b <p>One month ago, I saw someone's hobby OS and thought: "I want to build one too."</p> <p>One month later, nefuOS runs a browser, a compiler, a package manager, and a local LLM.</p> <h2> What it is </h2> <p>nefuOS is a full OS stack written from scratch:</p> <ul> <li> <strong>Ncore</strong> — custom kernel, boots via both BIOS (El Torito) and UEFI (GRUB multiboot2)</li> <li> <strong>Nbrower</strong> — custom browser with HTML/CSS/JS/WebGL2, own TLS 1.3 stack</li> <li> <strong>nefucpp</strong> — C++ → .nefud compiler</li> <li> <strong>NPKG</strong> — package manager over HTTPS, installs <code>.deb</code>-style packages</li> <li> <strong>Nshell</strong> — 60+ Unix-like commands</li> <li> <strong>Ngame</strong> — 34 built-in games</li> <li> <strong>NAI</strong> — a fine-tuned Qwen2.5-1.5B that actually calls tools (writes files, runs commands)</li> <li>Chinese IME, TTF rendering, 107 built-in apps</li> </ul> <h2> Screenshots </h2> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2F9wowrtxkrb2peoj544mg.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2F9wowrtxkrb2peoj544mg.png" alt=" " width="800" height="600"></a></p> <h2> The workflow: one dev + AI </h2> <p>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.</p> <p>Architecture, decisions, and debugging are mine. AI just made the typing faster.</p> <ul> <li>Self-developed: ~215k lines (C/C++ ~192k, Python ~24k)</li> <li>With third-party: ~1.04M lines</li> <li>One month</li> </ul> <h2> The hard parts </h2> <ul> <li> <strong>BIOS + UEFI dual boot</strong> — same kernel, two boot paths, one codebase</li> <li> <strong>TLS 1.3 from scratch</strong> — for the browser to talk to real sites</li> <li> <strong>QuickJS 2021 bugs</strong> — the old build crashes on a second <code>JS_Eval</code>; had to work around it</li> <li> <strong>SWGL</strong> — 9000 lines of software GL, needed to run WebGL2 without a GPU driver</li> </ul> <h2> What's next </h2> <ul> <li>bloxd.io WebGL rendering (canvas pipeline is almost there)</li> <li>Better CSS support (flexbox, descendant selectors)</li> <li>DeepSeek login fully wired into the browser</li> </ul> <p>GitHub: <a href="https://github.com/Nefu-Dev/nefuOS" rel="noopener noreferrer">https://github.com/Nefu-Dev/nefuOS</a></p> <p>Happy to answer questions about the architecture, the AI-assisted workflow, or the dual-backend design.</p> ai opensource programming showdev