Atom's developers describe it as "a hackable text editor for the twenty-first century." The core Atom editor comes with the standard suite of features most users expect in a programmer's editor: an integrated filesystem browser, version control integration, code auto-completion, multi-pane editing, and syntax highlighting for several dozen programming languages. But there are also over 8,500 add-on packages to contribute other capabilities. Among the currently featured packages are teletype (adding collaborative simultaneous editing), hydrogen (adding interactive code execution and debugging), and scroll-through-time (modifying two-finger scroll to move through time instead of space). Atom ships with four user interface themes, with more than 2,900 others available for download. Atom itself is an Electron application, built with HTML, CSS, and JavaScript, with plugins and themes written in those same technologies. The Atom website provides installers for Windows, macOS, and Linux systems. Many Linux distributions also include Atom in their official packages. Atom is free software, distributed under the MIT license, with source code available on GitHub.