OrbStack uses a lightweight Linux virtual machine with tightly-integrated, purpose-built services and networking written in a mix of Swift, Go, Rust, and C. See Architecture for more details.
It's using Apple Virtualization Framework + Rosetta acceleration instead of third party hypervisor like QEMU. There are ways to do this via the CLI with a simple one line command if you have Xcode installed.
It's a very interesting product, it does use a VM, but seems to have some "special sauce" code to improve the speed of things. It also says it shares the kernel among multiple VMs. Very cool stuff.
[1] https://orbstack.dev/