emfont is a free and open-source CJK webfont service. In production it lets websites load Traditional/Simplified Chinese, Japanese, and Korean fonts by injecting a small client script or CSS import. The server subsets original TTF/OTF files into minimal woff2 files on demand, serves pre-generated static font packs with unicode-range CSS, and exposes public APIs for font listing, font info, demo sentences, and bulletin messages. The backend is a Fastify Node.js application backed by PostgreSQL for catalog data, Redis for caching, and S3-compatible object storage (Cloudflare R2/MinIO) for font binaries; it also includes a full admin console for font upload, original-file verification, user management, and static font regeneration jobs.