MultiFirefox

This utility provides a simple way to launch several installations of the Firefox web browser simultaneously on macOS. It creates separate processes for each selected version, allowing users to keep distinct profiles, extensions, and settings isolated while they run in parallel. The launcher handles the necessary command‑line arguments and environment configuration so that each instance operates independently without interfering with the others.

Target users include developers, QA engineers, and power users who need to test web content across different Firefox releases or maintain separate browsing environments on the same machine. By centralizing the launch process, the tool removes the need to manually manage multiple application bundles or tweak system settings for each version.

The application is packaged for macOS, marked as stable, and focuses on the core functionality of side‑by‑side execution. It does not provide additional features beyond launching the browsers, keeping the implementation lightweight and purpose‑driven.