Portable Virtualbox is not available for Mac but there are some alternatives that runs on macOS with similar functionality. The best Mac alternative is VirtualBox, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Portable Virtualbox and seven of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Portable Virtualbox are QEMU (Free, Open Source), Parallels Desktop (Freemium), VMware Fusion (Free Personal) and Multipass (Free, Open Source).
Parallels Desktop gives Mac users the ability to run Windows, Linux or any other operating system and their critical applications at the same time as macOS. Parallels Desktop is optimized for Intel and Apple M1 chip.
Multipass is a lightweight VM manager for Linux, Windows and macOS. It's designed for developers who want a fresh Ubuntu environment with a single command. It uses KVM on Linux, Hyper-V on Windows and HyperKit on macOS to run the VM with minimal overhead.
PCE is a collection of microcomputer emulators. At the moment it contains three emulators: PCE/atarist is an Atari ST emulator. It emulates the various ST and Mega ST models. PCE/ibmpc is an IBM PC 5150 emulator. It emulates an IBM PC 5150 or an IBM PC/XT 5160.
Lima launches Linux virtual machines on macOS, with automatic file sharing, port forwarding, and containerd. Lima can be considered as a some sort of unofficial "macOS subsystem for Linux", or "containerd for Mac".