Open a browser anywhere and your development environment is already there: Atheos is a full code editor that runs on your server instead of your laptop, complete with projects, plugins, and multi-user accounts. The three-panel layout keeps the file and project manager on the left, a split-able editing area in the center, and system and plugin controls tucked on the right. Syntax highlighting covers more than 40 languages with over 20 color themes, smart auto-complete speeds up the typing, and error checking flags problems as you work. Multiple users get their own accounts, and real-time collaborative editing puts several cursors in the same file without merge chaos later. Advanced search tools sweep across project files, LocalStorage redundancy protects unsaved work against a dropped connection, and quick-download backups package a project in one click. A plugin library and marketplace extend the editor, from terminal access to Git tooling, and internationalization translates the interface for the rest of the team. There is no database to run: Apache and PHP on your server are the entire stack. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.