What is rbxmulti-loader?

This repository is a small Windows utility that lets a player run more than one copy of Roblox at the same time on the same computer. Normally Roblox blocks multiple instances by locking a shared system resource so only one game window can run at once. This tool works around that lock by closing the specific handles Roblox uses to enforce it, each time a new instance is launched. It works entirely through PowerShell, with no separate executable file needed. During installation, it registers a custom link format called rbxmulti, which behaves like Roblox's own launch links but routes through this tool first. When a player clicks a launch link using this custom format, the script closes the singleton lock in any Roblox processes already running, starts a new Roblox window using the standard Roblox launch protocol, and then patches the lock again in the background for the newly opened instance. The tool also installs a small local web server that runs quietly in the background and restarts automatically on login, which browser extensions can query to check whether the tool is installed. Installation is done with a single PowerShell command that downloads the repository, copies its files into the user's local application data folder, and registers everything needed to start automatically. An uninstall script is provided to remove the URI handler, stop the background server, and delete the installed files. The repository also documents where to find its log files if something needs troubleshooting. The project is released under the MIT license and includes a clear disclaimer stating that it is not affiliated with Roblox Corporation, that it works by closing process handles at runtime, and that it is used at the user's own risk. It is aimed at Roblox players on Windows who want to run multiple accounts simultaneously and are comfortable running PowerShell scripts and browser extensions that talk to a local server.