| Component | Technology | Role | | ----------------- | ------------------------ | -------------------------------------------------------------------- | | | HTML5, JavaScript, Ace | Browser-based editor UI, file tree, terminal emulator. | | WebSocket server | Node.js (Express + Socket.IO) | Handles real‑time collaboration, file watching, terminal I/O. | | Backend bridge | c9/inspector (Node.js) | Spawns child processes (shell, linters, debuggers). | | Project runtime | Docker (optional) | Isolated workspace per user (recommended for security). |
However, in 2026, it should be treated as a , not a general‑purpose IDE server. For new projects, invest in Theia or code‑server – but if you need a battle‑tested, no‑frills web IDE that runs on a Raspberry Pi, the old c9 still delivers. private server c9
(using a manager script). This prevents users from seeing each other’s files or crashing the host. 6. Hardening & Security Considerations | Threat | Mitigation | | ------------------------------- | -------------------------------------------------------------------------- | | Arbitrary command execution | Run as non‑root user; use --cap-drop=ALL in Docker. | | File system escape | Workspace chroot / bind‑mount to a dedicated directory. | | Resource exhaustion | Docker --memory="512m" --cpus="0.5" . | | Plaintext passwords | Terminate with HTTPS (nginx reverse proxy + Let's Encrypt). | | Session hijacking | Enable -s (secure cookies) and force WebSocket over WSS. | | Brute force | Put behind Authelia, OAuth2 Proxy, or Cloudflare Access. | Nginx reverse proxy example (HTTPS + WebSocket) server listen 443 ssl; server_name c9.example.com; ssl_certificate /etc/letsencrypt/live/...; location / proxy_pass http://127.0.0.1:8181; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_set_header Host $host; | Component | Technology | Role | |
All can be self‑hosted with Docker and offer LSP, debuggers, and Git integration out of the box. The legacy Cloud9 private server is a hidden gem for ultra‑lightweight, ephemeral, or offline development. Its small memory footprint (~80 MB idle) and real‑time terminal make it ideal for IoT device coding, secure facility workstations, or teaching programming on low‑cost Chromebooks. | | Project runtime | Docker (optional) |
with Node 16 and c9 pre-installed:
FROM node:16-bullseye-slim RUN apt update && apt install -y git curl build-essential python3 psmisc && git clone https://github.com/c9/core.git /c9 && cd /c9 && npm install --production