MultiLaunchBox is described as 'mong the first Mac multi-boxing applications to handle not only keybroadcasting but also application launching'. There are eight alternatives to MultiLaunchBox for Windows and AutoHotkey. The best alternative is Input Director. It's not free, so if you're looking for a free alternative, you could try Mini Mouse Macro or keystarter. Other great apps like MultiLaunchBox are Quick Macros (Paid), Buttoncommander (Paid), Keyclone (Paid) and ISBoxer (Paid).
Input Director is a Windows application that lets you control multiple Windows systems using the keyboard/mouse attached to one computer. It is designed for folks who have two (or more) computers set up at home and find themselves regularly sliding from one system to the other.
HotkeyNet is free multiboxing software. It's a hotkey program for gamers who play several characters at the same time. It lets you control several programs on your network from any keyboard no matter which PCs the programs are running on.