Usefulness

How is this emulator useful?

• It's an exercise in writing portable code.
• It's an exercise in writing fast code.
• It's a rather simple, but complete, implementation of an x86 CPU in software.
• You can use the #defines in include/cpu/cpu.h in other projects.
• Push the WebAssembly engine in modern browsers to its limit. How well does Firefox boot Windows XP?
• Test unusual and rare combinations of hardware and software. It is possible for you to emulate a Pentium 4 system with only an ISA bus.
• Running old games on modern systems. I played Reversi in my browser for an hour and lost every single game.
• Running system utilities. I use Halfix to format all my hard drive images with a FAT32 operating system.
• Running programs that no longer work on modern systems. I created Halfix because I needed a secure environment to run a web application that used VBScript and targeted Internet Explorer 6.
• Self-virtualization (not really useful from a practical perspective, but still very cool).