Github developed Atom and supports Windows, Linux, macOS. By Default, support popular languages - JavaScript, NodeJS ,typescript, and Nodejs

It is a Desktop application built using ElectronJS and CoffeeScript.

It is fully customizable using Javascript via plugins as well as init scripts.

Atom editor features

- Debugging
- Included GitHub support
- Syntax highlight
- Extend plugin support
- Inbuilt Debug Support
- Git Plugin
- SSH integration
- Terminal
- Code Snippets
- Code refactoring
- Support for  popular programming languages
- Autocomplete
- Linter and format
- teletype feature that shares your workspace and code with teams
- Search files
- File browser

Atom Editor size is 80 to 100MB in windows.