Cheat Engine:DBVM
DBVM is a hypervisor that will load your current OS. Windows, 32-bit or 64-bit, and even linux.
If it's active it provides several useful tools for gaining access to the core of the system. Like raising privilege, hooking interrupts without editing the IDT, etc...
It's also semi-popular in the use of some selective botting tools since it provides raw access to the keyboard and mouse hardware/ports
It's most useful in 64-bit. Here hooking of interrupts using the IDT isn't possible, and there is no os specific function to hook system interrupts like int1. It's also not possible to load an unsigned driver, which is a big annoyance for people that generally never sign their stuff. With the use of DBVM though, you can hook the system interrupts, and because you can raise privilege from ring3 to ring0 you can then also manually load your driver into the OS