Concurrently is a command-line tool that runs multiple commands in parallel with better output management and process control than shell backgrounding.
The tool solves the problem of running several long-lived processes together while keeping their output readable and manageable. When you run commands with shell operators like `&`, outputs interleave confusingly and a single process failure goes unnoticed. Concurrently prefixes each command's output with its name, making it easy to track which process produced which lines. It offers a `--kill-others` switch that terminates all remaining processes if any one of them exits, preventing zombie processes from continuing silently in the background.
Concurrently suits development workflows where you need multiple watchers or servers running together, such as watching JavaScript and CSS files simultaneously or running a development server alongside a build watcher. It works cross-platform including Windows, and despite being written in Node.js, it can run any executable commands. The tool can be installed globally for system-wide use or locally as a dev dependency in a project's npm scripts.
The project maintains steady activity with regular updates addressing edge cases and platform-specific issues. Maintenance includes ongoing refinement of Windows compatibility and handling of various shell quoting scenarios. The codebase receives consistent attention to documentation and user-reported problems, with fixes deployed for issues ranging from signal handling to output formatting across different operating systems.
